Anesthesia Study Questions Flashcards

coronary blood flow
Terms Definitions
What are acceptable levels in parts per million (ppm), of inhaled anesthetics in the operating room when N20 and a volatile agent are used together?

When a Volatile agent is used alone?
N20 and Volatile agent together, the UPPER limit for N20 is 25 ppm and the volatile agent = 0.5 ppm.

When a volatile agent is used alone, the upper limit is 2 ppm
Where and how is N20 metabolized?
N20 is Metabolized to N2 in the intestines by anaerobic bacteria
What are 2 effects of halogenating inhalational agents?
1. Decreases Flammability
2. Reduces Toxicity
MAC of an inhaled agent is inversely proportional to what?
POTENCY - the lower the MAC, the greater the potency
List 7 factors that that decreases MAC.
1. Old
2. Hypothermia
3. CNS depressants
4. Acute ETOH
5. Alpha - 2 - Agonist
6. Pregnancy
7. Decreased levels of CNS excitatory NT (as with resperpine)
Which electrolyte abnormality will cause MAC to increase?

to Decrease?
Increase MAC - HYPERnatremia

Decrease MAC - HYPOnatremia, and HYPERcalcemia
At what age are MAC values highest for most volatile agents?

Which volatile is the exception?
For most volatile agents, the highest MAC values are for infants 1-6 MONTHS.

Sevo is the exception. MAC is the highest in neonates 0-30 DAYS

overall- there is a 30% greater VA requirement in infants when compared to results
List 4 ADVERSE side-effects of N20.
1. Aplastic Anemia (immature RBC)
2. Congenital Anomalies
3. Spontaneous Abortion
4. CNS Toxicity
Does N20 administered alone increase CBF and ICP?
Why does N20 by itself produce an increase in both SVR and PVR?
N20 has a mild sympathomimetic effect
Which ester LA is a weak acid?

What is the pKa?
1. Benzocaine is a weak acid

2. pKa = 3.5

All other LA are weak bases - 7.6 to 9.1
What form - mostly ionized or mostly nonionized - exists when Benzocaine encounters physiologic pH?
pKa of Benzocaine = 3.5 (weak acid). Put into a basic solution = more ionized.
1. What is the recommended dose of Benzocaine?

2 What is the pKa?

3. What potentially life-threatening complication may ensue if the typical dose is exceeded?
1. 1 spray = 20% = 200 mg/ml
2. pKa = 3.5 (weak acid)
3. Methemoglobinemia (if dose exceeds 200-300 mg) - Tx with Methylene Blue 1-2 mg/kg
4 steps involved in primary hemostasis..
1. adhesion (DC Government)
2. activation
3. aggregation
4. production of fibrin
Platelets have a life span of how many days?
8-12 days
Normal platelet count is?
Approx _____% of platelet pool is sequestered in the speen
What anchors the platelets to the wall of the damaged blood vessel?
4 steps involved in primary hemostasis..
1. adhesion
2. activation
3. aggregation
4. production of fibrin
platelets have a life span of .....
8-12 days
nl platelet count is....
Approx _____% of platelet pool is sequestered in the speen
What anchors the platelets to the wall of the damaged blood vessel?
vWF anchors platelets to the _____ layer of the _______.

vWF is synthesized and released by ______ .
Endothelial Cells
______ is the most common inherited coagulation defect
von Willebrand's
1. DDAVP causes.....

2. a side effect of DDAVP administration is...

3. occurs in _______

1. Release of endogenous vWF.

2. Hyponatremia

3. Mostly children

4. 0.3ug/kg IV for 15-20 minutes
1st line treatment for factor VIII deficiency?
2nd line tx?
3rd line tx?
1st. DDAVP.....vWF
2nd. Cryoprecipate
3rd. Factor VII concentrate
Hemophilia A is a deficiency of ____


Best is factor VIII concentrate
What gas law describes the operation of a bellow ventilator?
Boyle's Law (Bellow=Boyle's)
An E cylinder of O2 will empty 625 Liters into the atmosphere. What law applies?
Boyles Law. P and V are inversely related, IF TEMP is constant.
What is the partial pressure of nitrogen at 1 atmosphere? What applies?
N2 is 79% of the atmosphere.
Partial Pressure of N2 at 1 atm = 0.79 X 760 = 600 mmHg.
Law = Dalton Law of Partial Pressures.
Hemophilia B is a deficiency of which factor?

Hemophilia B is a deficiency of factor 9- Christmas disease.

TX: Factor 9 concentrate
Closing Capacity is defined as:___________ + _________ .
Residual volume + Closing volume. Closing capacity is the volume at which the airways BEGIN to close.
Most abundant component of the cell membrane based on # of molecules?

Most abundant based on weight?
Phospholipids based on #

Proteins based on weight
Non-polar molecules readily dissolve in _______ .

This is called ________ .
Lipids (lipophilic and hydrophobic).
By what process are neurotransmitters released from the nerve terminal?
Name 5 2nd messengers?
Chemicals generated inside the cell by enzymes facing inward from the cell membrane are 2nd messengers. The exception to this the enzyme_______ . This projects outward in order to ___________ .

metabolize acetylcholine.
Name the three G protein sub units.....
Alpha, Beta, and Gamma
One treatment for hyperkalemia is insulin. what is the mechanism of action?
Stimulates the Na+ - K+ pump to drive K+ back into cells. Beta 2 agonists also work on the pump to drive K into cells (terbutaline, albuterol, ritodrine)
Resting Membrane potential in excitable tissues (neurons, skeletal muscles, smooth muscle, and cardiac muscle is determined mostly by which ion?
What is resting membrane potential in nerves?

What is resting membrane potential in the heart?
Nerves = -70 mv

Heart = -90 mv
In the neuron, where are voltage gated sodium channels found?
In the neuron, where are voltage gated sodium channels found?
One treatment for hyperkalemia is insulin. what is the mechanism of action?
Stimulates the Na+ - K+ pump to drive K+ back into cells. Beta 2 agonists also work on the pump to drive K into cells (terbutaline, albuterol, ritodrine)
Resting Membrane potential in excitable tissues (neurons, skeletal muscles, smooth muscle, and cardiac muscle) is determined mostly by which ion?
In the neuron, where are voltage gated sodium channels found?
Name 3 clinical examples of sodium channels being in the "inactivated state" or the absolute refractory period......
1. High potassium in cardioplegia solution - causes membrane depolarization
2. Sucinnylcholine - depolarization of skeletal muscle motor end plate
3. Local anesthetics- interrupt nerve conduction
Motor nerves are _______ and exit the ______ ______. Sensory nerves are _______ and enter the ______ _______.
Motor are efferent and exit ventral cord. Sensory are afferent and enter the dorsal horn.
How many molecules of Ach are needed in the post synaptic nicotinic recpetor?
2 molecules of ACh are needed. (Diacetylcholine!)
What is the primary route of elimination for vecuronium and rocuronium?
Biliary excretion (AKA hepatic or liver)
How is Atracurium eliminated?
ester hydrolysis (nonspecific esterases) and Hoffman elimination (pH and Temp-dependent degradation)
How is cisatracurium eliminated?
Hoffman elimination ONLY (pH and Temp-dependent degradation)
How is mivacurium eliminated?
Plasma Cholinestrases (Same as succinylcholine)
What Neuromuscular blocking agents can release histamine?
Histamine Sux I M MAD
1. Succinylcholine
2. Mivacurium
3. Metocurine
4. Atracurium
5. d-tubocurarine
Which Neuromuscular blocking agents have vagolytic responses? There are 2.......
1. Pancuronium
2. Gallamine
How would you minimize the histamine release while giving Mivacurium?
Low dose. Doses UNDER 0.25 mg/kg and SLOW IVP
If you are using a nerve stimulator on the right wrist of a patient with right sided hemiplegia, will the twitch be less than, same as, or greater than the twitch on the left?
GREATER.........R>L.......Nicotiic receptors are up-regulated on the right.
What is the earliest and most sensitive sign of MH?
Unexplained doubling or tripling in ETCO2.
Blockage of what percent of motor end plate nicotinic receptors is adequate for
1. intubation?

2. For abdominal procedures?
1. 95%
2. 90%
4 routes of elimination of Norepiniephrine are.......
1. Re-uptake (80%)
2. Diffuse away
3. MAO
Id muscles that abduct and adduct the vocal cords
posterior cricoarytenoids abduct and the lateral cricoarytenoids adduct
What is the anatomic dead space in the adult?
2 cc/kg
How can you calculate how much O2 is dissolved in the blood. What law applies?
Multiply PO2 x 0.003. Henry's law
True or False

All sympathetic preganglonic fibers pass thru white rami enroute to the paravertebral ganglia.
Compared with skeletal muscle, what protein is NOT found in smooth muscle?
Smooth muscle does NOT contain the regulatory troponin protein complex
How does contraction proceed in skeletal or cardiac muscle after calcium combines with troponin?
After Ca+ combines with troponin, tropomyosin is repositioned so that sites on actin are exposed, and myosin cross-bridges attach to these exposed actin sites and pull. Actin-myosin interaction is the cause of contraction
Which volatile agent is completely halogenated with fluorine?
Desflurane (a methyl ethyl ether) is completely halogenated with fluorine. Even though sevoflurane has only fluorine as the halogen substitutions, sevo is NOT considered completely halogenated.
What is indicated by a V/Q ratio that is greater than one?
(V/Q > 1)
V/Q over 1 indicates dead space
In a lung unit that exhibits absolute shunt, what is the V/Q ratio?
What is the amount of ventilation?
What is the amount of perfusion?
In a lung unit that exhibits absolute shunt, V/Q=0 because V=0; Perfusion (Q) may be decreased because of hypoxic pulmonary vasoconstriction. (HPV)
What identifies myocardial ischemia during surgery?
On the EKG, ST segment depression of greater than 1 mm provides evidence of myocardial ischemia
How long does it take an infarcted area of the heart to heal?
Most of the final stages of recovery are achieved within 5-12 weeks, though some recovery continues for 6 months.
What is the intrinsic firing rate of the SA node?
AV Node?
Purkinje network?
SA node = 60-100
AV Node = 40-60
Perkinje network = 15 - 40
What is the oxygen consumption rate of the heart?
8 - 10 ml O2/100g/min
what 4 factors determine myocardial oxygen demand?
1. Preload (Diastolic wall tension)
2. Afterload (Systolic wall tension)
3. Contractility
4. Heart Rate
What is the range for coronary perfusion pressure?
Coronary blood flow is autoregulated when coronary perfusion pressure ranges from 60 mmHg - 160 mmHg.
What percentage of cardiac output perfuses the heart?
4 - 5 %
What percentage of cardiac output is delivered to the highly-perfused organs? Heart, brain, kidneys, and liver)
Approximately 75% of resting cardiac output is delivered to vessel rich organs, although they only constitute 10% of total body mass.
what nerves carry the afferent and efferent signals of the Bainbridge reflex?
When the great veins and right atrium are stretched by increased vascular volume, stretch receptors send afferent signals to the medulla via the vagus nerve. The medulla then transmits efferent signals by the sympathetic nerves to increase HR and contractility.
What does the Bainbridge reflex help prevent?
The Bainbridge reflex helps prevent damming up of blood in the veins, the atria, and the pulmonary circulation.
Where is Angiotensin I converted to Angiotensin II?
In the pulmonary vasculature of the lung.
What is the range of normal pressures in each chamber of the heart?
RA = 1 - 8 mmHg
RV= 15 - 30 mmHg

LA = 2 - 12 mmHg
LV = 100-140 / 0-12 mmHg
Define ejection fraction.

What is normal ejection fraction?
EF = SV / EDV.....or
EF = (EDV - ESV) / EDV

Normal EF = 0.6-0.8 (60-80%)
What is normal range for stroke volume in a 70 kg male?
60-90 ml
What is stroke volume index?

What is normal SVI?

Normal SVI = 40 - 60 ml/beat/m2
What are the actions when the oxygen low pressure alarm sounds?
Fully open the E cylinder

Disconnect the pipeline

Consider low gas flows
At what pressure does the fail-safe valve shut off the flow of N2O or other gases?
Line pressures of less than 30 psi will usually close the flow of all gases, except oxygen, to the common gas outlet.
at what gestational age does the risk of retinopathy of prematurity become negligible? Why?
The risk of retinopathy of prematurity becomes negligible after 44 weeks postconception because retinal vasculogenesis is complete between 42-44 weeks postconception.
CPAP during one-lung ventilation is applied to which lung at what pressure?
CPAP is applied to the collapsed (non-dependent) lung at a pressure of 5 - 10 cm H2O
What are the 2 most common indications for pacemakers?
Sick Sinus Syndrome and complete heart block (third degree)
Norepinephrine is released from ALL post ganglionic nerves except in the ________ _________ . In this part of the body, _________ is released instead of NE.
Sweat Glands

The adrenal medulla is innervated by sympathetic _____ganglionic neurons.
The adrenal medulla is innervated by PRE ganglionic SNS neurons and release NE and EPI. (80% EPI and 20% NE)
1. What neurons conduct action potentials faster, those with large diameters or smaller diameters?

2. Which type of neurons have the largest diameter?

3. Which type of neurons have the smallest diameter?
1. Large diameter neurons conduct action potentials at greater speeds.

2. Largest = A-alpha (12-20 microns)

3. Smallest = C fibers (non-myelinated) 0.4-1.2 microns
Which type of neurons are preganglionic autonomic neurons?
B fibers - myelinated - 3-15 microns
Which type of neurons are postganglionic sympathetic neurons?
C fibers - non-myelinated - 0.3-1.3 microns
The stellate ganglion is formed by what 2 structures?

If the stellate ganglion is blocked what syndrome will the patient have?

What are the symptoms?
Stellate Ganglion is formed by the inferior cervical ganglion and the thoracic ganglion. If blocked = Horners syndrome. Symptoms: IPSILATERAL Ptosis, anhydrosis, miosis,enopthalmosis, flushing, nasal congestion
The cardioaccelerator fibers arise from what spinal cord segments?
T1 -T4
What substances are made by the breakdown of norepinephrine?
Vanillylmandelic acid (VMA) and metnorepinephrine
What agents should be avoided when a patient is taking an MAO inhibitor?
Indirect-acting sympathomimetics such as ephedrine and meperidine. When either of these are given to a patient taking an MAO inhibitor it may trigger an HTN-crisis. (Meperidine >Ephedrine)
Stimulation of Beta-2 receptors on the liver will cause________ + _________ .
1. Glycogenolysis: Breakdown of glycogen to glucose.

2. Glyconeogenesis: Formation of new glucose from non-carbohydrate sources (amino acids)

Both processes increase blood. sugar
1. Where is Renin released from?
2. What percentage of resting BP is controlled by Renin?
3. What does Renin do?
1. Renin is an enzyme released from the juxtaglomerular (JG) cells of the afferent arteriole in the kidney.
2. 85%
3. Renin converts angiotensinogen from the liver to angiotensin I.
What triggers Renin release from the JG cells of the afferent arterioles? (2 answers)
1. Decreased renal artery BP
2. Increased sympathetic nerve activity
Angiotensin I is converted to angiotensin II by what enzyme?

Where is this enzyme found?
1. ACE - Angiotensin Converting Enzyme

2. Endothelial surface of pulmonary capillaries.
Angiotensin II promotes ________ and ________ .
AT II promotes vasoconstriction and aldosterone release.
What are the stimuli for aldosterone release?

What does aldosterone do?
Angiotensin II and increased serum k+. Aldosterone increases sodium reabsorption to volume expand and increases K+ secretion (excretion)
How does Epinephrine or Isoproterenol decrease diastolic BP?
By stimulation of Beta-2 receptors which leads to vasodilation and decreased SVR.
Name 3 centrally acting sympathomimetics?
1. Alpha-methyldopa
2. Clonidine
3. Dexmedetomidine

All work on Alpha 2, negatively coupled recepter.
Name 3 centrally acting sympathomimetics?
1. Alpha-methyldopa
2. Clonidine
3. Dexmedetomidine

All work on Alpha 2, negatively coupled receptor.
Name 2 non-selective alpha-adrenergic antagonists?
Phenoxybenzamine and Phentolamine.

Both are Alpha-1 > Alpha 2
Which medication is used to control BP in patient's with pheocromocytoma?
Phenoxybenzamine - a long acting non-selective alpha-adrenergic antagonist.

Patients with pheocromocytoma should be alpha blocked prior to beta blocked or else may cause heart failure. Alpha block causes arterial dilation and decreased SVR/afterload. These changes make it easier for the heart to eject blood after beta blockade.
What is Prazosin?
What is it used for?
Prazosin is a selective alpha-1 adrenergic antagonist that lowers BP without increasing the release of NE from postganglionic nerve terminals because it does not block alpha-2 receptors.
In terms of cardiac beta receptors, chronic expose to an agonist will cause __________ . an example of this is in a patient with _____ .
Down regulation of receptors occurs after chronic administration beta agonists as in a patient with CHF.
Which cranial nerves are involved in the outflow of information from the PNS?

Which is the dominant nerve?
III - Occulomotor - From Midbrain
VII - Facial - From Pons
IX - Glossopharyngeal - From Medulla
X - Vagus = DOMINANT (75%) - From Medulla
What is the major cation inside the neuron? Outside?
K inside.

Na outside
What is the most common excitatory nerurotransmitter in the CNS?
In the supine position what it the highest point of the spinal column?

Lowest point?
L3 highest
T6 lowest
What types of peripheral nerves carry only motor info?
B fibers
What % of CO is CBF?
Which sacral nerves comprise the PNS?
S2, S3, S4

PNS = Craniosacral
What are the actions of the PNS at Muscarinic receptors?

At Nicotinic receptors?
Muscarinic - Bradycardia, Increased gastric secretions, Hyperperistalsis, Miosis, Salivation.

Nicotinic - Stimulation of autonomic ganglia and stimulation of neuromuscular junction
Echothiophate is a ___________ .

It is used for ___________ .

Actions of which drugs will be prolonged if a patient is using echothiophate and why?
Echothiophate is cholinesterase inhibitor. It is used for glaucoma. Patients on echothiophate have decreased levels of plasma cholinesterase activity, so actions of succinylcholine and mivacurium are prolonged.
1. Which antimuscarinic causes the most sedation?

2. Which antimuscarinic causes the most increase in HR?

3. Which antimuscarinic causes the most antisialagogue effect?
1. Scopolamine
2. Atropine
3. Scopolamine
1. Which patients are most sensitive to antimuscarinics and most likely to experience anticholinergic syndrome?
2. How do you treat anticholinergic syndrome?
3. What is the dose?
1. Pediatric and geriatric patients
2. Physostigmine (cholinesterase inhibitor)
3. 15 - 60 mcg/kg IV
Which first messenger does NOT bind to a cell membrane receptor?
Nitric Oxide does not bind to a membrane-embedded receptor, yet it is a first messenger. NO readily permeates lipid membranes owing to its small size and lipid solubility.
How is hypercalcemia treated?
Initially with normal saline and furosemide given IV. Emergency tx is when serum Ca2+ is >15mg/dl. A bisphosphate can also be administered (7.5mg/kg IV for 3 days)
What 3 forms of Ca2+ are used to treat hypocalcemia? Over what period of time is the Ca2+ administered and how much is given?
Treatment is with CaCl, Calcium gluconate and Calcium gluceptate. It is adm. over 5 to 15 minutes. CaCl is given 3-6 mg/kg and calcium gluconate is given 7-14 mg/kg
What is the most significant effect of Hyperphosphatemia? Why does it occur?
Hypocalcemia. With severe hyperphosphatemia, calcium phosphate deposits in bone and soft tissue, thereby lowering plasma calcium concentration
What are signs and symptoms of severe hyperphosphatemia?
Related to associated hypcalcemia: increased excitability of nerves (threshold potential moves toward resting membrane potential) resulting in paresthesia (tingling lips and fingers), laryngeal stridor, Trousseau's sign (carpopedal spasm), Chvostek's sign (masseter muscle spasm), and seizures. Prolongation of QT interval
How is hyperphosphatemia treated?
Aluminum based antacids and sucralfa (Carafate). Calcium citrate, calcium carbonated, and dialysis
How is hypermagnesium treated?
IV calcium gluconate at 10-15 mg/kg followed by fluid loading and an IV diuretic
The ECG of the renal failure patient reveals a prolonged QT interval? What is the problem? Why does this problem occur?
The patient in chronic renal failure my have electrolyte disturbances, including hyperkalemia, hyperphosphatemia, and hypocalcemia, that alter ECG. A prolonged QT interval suggests hypocalcemia. This results from hyperphosphatemia and impaired intestinal absorption of calcium
List five pulmonary function chnages associated with a pneumoperitoneum
1. increased peak inspiratory pressure, 2. decreased vital capacity 3. decreased functional residual capacity 4. increased intrapleural pressure and 5. decreased respiratory system compliance
Explain how a CO2 embolus during laparscopic surgery may produce a decreased ETCO2
CO decreases and the physiologic dead space increases leading to decreased ETCO2. Initially ETCO2 may increase from pulmonary excretioni of absorbed CO2, as expected during a CO2 embolus. The initial increase in ETCO2 is then followed by a decrease
What is bone cement implantation syndrome?
Occurs when hypotension is accompanied by hypoxia, dysrhythmia, pulmonary hypertension and decreased CO
Should you put the blood pressure cuff on the left or the right when the patient is undergoing mediastinoscopy? Why?
The BP cuff should be placed on the left. A drop in blood pressue in the left suggests hemorrhage, the most frequent severe complication of mediastinoscopy.
What three vessels can be compressed by the mediastinoscope?
Innominate artery may be compressed which in ter will cause cessation of flow through the vessels arising from the innomiate, the right carotid arter and the right subclavian arter.
What are the consequences of compression of each of the vessels compressed during a mediastinioscope?
Compression of the right innominate or carotid vessels could decrease cerebral perfusion if the patient has CVD. Collater flow through the circle of Willis would be expected to maintian cerebral flow in healthy patients. Compression of the right subclavian arter will result in a loss of pulse and pressure in the right arm
What pulmonary function test best assesses small airway disease?
Forced expiratory flow between 25 and 75% of forced vital capacity. FEF25-75 is also known as mid-maximal expiratory flow MMEF.
What causes the crisis in sicle cell patients?
When HgbS is exposed to low concentration sof O2, precipitates of long crystals form which damage cell membrances of re blood cells, resulting in seriuous anemia. Crisis implies low O2 tension causing sickling which results in decreased blood flow through tissues causing a serious decrease in red blood cell mass withing few hours, leading to death.
What drug might you give along with atropine to treat organophosphate poisoning?
Pralidoxime may be given with atropine because it reactivates acetylcholinesterase.
What is the treatment for cholinergic syndrome? What dose?
Atropine is given for cholinergic syndrome (cholinergic crisis). 35 - 70 mcg/kg every 3 -10 minutes.
(or 0.04 - 0.07 mg/kg q 3 - 10 min)
How is cholinergic syndrome diagnosed?
Gradual injection of edrophonium to a maximum dose of 10 mg in a 70 kg patient.
If the patient gets better - Myasthenic crisis.
If the patient gets worse- cholinergic crisis.
List 6 reasons for failure of a max dose of anticholinesterase to fully reverse NDMB.
1. Insufficient time elapsed to work
2. Degree of blockade is too intense
3. Low body temperature
4. acid/base or e-lyte disturbance
5. Patient is recieving drugs that interfere
6. Clearance of NDMB is reduced by renal or hepatic disease
Rank the order of anticholinesterase and anticholinergic agents based on onset (fastest to slowest).
Atropine (1-2 min)
Glyco (2 min)
Edrophonium (5-10 min)
Neostigmine (5-15 min)
Pyridostigmine (10-20 min)
How does edrophonium bind to acetylcholinesterase?
Edrophonium binds electrostatically to the anionic site of acetylcholinesterase and forms a hydrogen bond with the electrostatic site.
How does neostigmine and pyridostigmine bind to acetylcholinesterase?
Neostigmine and pyridostigmine bind covalently with acetylcholinesterase at the esteratic site to form an inactive complex.
Which of the 4 common anticholinesterase agents is NOT a quaternary ammonium?
Physostigmine is a tertiary amine. Physostigmine is NOT used to reverse NMB because the dose required to achieve this effect is excessive.
In patients with low concentrations of normal plasma cholinesterase, how much is the duration of NMB prolonged?
The duration of NMB by Succs is doubled or tripled (slightly prolonged). M&M p.154
Identify the incidence of heterozygous atypical plasma cholinesterase in the general population.

Identify incidence of homozygous.....
Heterozygous= 1:25 or 4%
Homozygous= 1:2800 or 0.04%
Which agents have prolonged action in patients with atypical pseudocholinesterase (3)?
1. Succs
2. Mivacurium
3. Ester-type Locals
How is the Dibucaine # used to test for pseudocholinesterase activity?

What is normal range?
Range for homozygous?
Range for heterozygous?
Dibucaine supressed the activity of pseudocholinesterase. If pseudocholinesterase is normal, dibucaine will depress the activity of pseudocholinesterase by 70-85% (called the dibucaine #).
Normal range= 70-85
Homozygous = 20 (16-25)
Heterozygous = 40 - 60
How is anticholinergic syndrome treated?
IV physostigmine. Slow IV at a dose of 15-60 mcg/kg. Repeated doses may be necessary because it is metabolized rapidly.
What is the significance of excessive salivation in a patient with myasthenia gravis?
The presence of muscarinic SE (such as salivation, miosis, bradycardia) is due to excessive anticholinesterase drug effects. This along with skeletal muscle weakness is known as cholinergic crisis.
Do antimuscarinics interfere with sweating?
YES. large doses of atropine may increase body temp by preventing sweating. Recall that acetylcholine is released to muscarinic receptors of sweat glands from sympathetic postganglionic neurons.
What is the appropriate premedication dose of atropine for the adult with severe bradycardia?
IV or IM 0.01-0.02 mg/kg up to the adult dose of 0.4-0.6 mg/kg. larger doses up to 2 mg may be required to completely block the cardiac vagal nerves in treating severe bradycardia.
When is scopaolamine preferable to atropine?
Scopolamine is a more potent antisialagogue, more useful for sedation and amnesia, and has minimal cardioaccelerator effects. Scopolamine should be used if an increase in HR is undesireable, if decreasing secretions is important, or if antiemetic effect is desired.
State 5 reasons for giving antimuscarinics.....
1. Antisialagogue effect
2. Sedation and amnesia
3. Increase in HR
4. Bronchodilation
5. Reversal of cholinergic crisis
What does increased magnesium do to NDMB? How does this happen?
NDMB is enhanced by increased magnesium levels.
Magnesium decreased acetylcholine release from nerve terminals and reduces sensitivity of the post junctional membrane to acetylcholine.
What antibiotics prolong the action of NDMB?

Which antibiotics do not interfere with NDMB?
Enhance block = aminoglycosides

No effect = PCN and cephalosporins
Name 3 aminoglycosides antibiotics.

What 2 are most potent in depressing neuromuscular function?
Aminoglycosides- Neomycin, streptomycin, kanamycin.

neomycin and streptomycin are the most potent in depressing neuromuscular function.
What 2 ways do aminoglycosides potentiate NDMB?
1. Depress release of acetylcholine similar to that of Mg2+.

2. They have post-junctional depressant activity.
what does cAMP do in motor nerve terminals?
cAMP, a second messenger, opens calcium channels, permitting more calcium to enter, and increases the release of acetylcholine.
Does furosemide enhance or antagonize NDMB?
Furosemide decreases cAMP in the motor nerve terminal. Ca+ entry decreases as cAMP decreases and acetylcholine release decreases when less Ca+ enters the nerve terminal. ACh release is reduced, so NDMB is enhanced.
What effect does lithium have on depolarizing and NDMB's?
Lithium potentiates the action of both depolarizing and NDMB's.
Identify 6 metabolic or electrolyte disorders that prolong/increase NDMB?
1. Respiratory acidosis
2. Metabolic alkalosis
3. Hypothermia
4. Hypokalemia
5. Hypercalcemia
6. Hypermagnesemia
How are the actions of acetylcholine and Succs terminated?
Succ is enzymatically hydrolyzed by plasma cholinesterase. ACh is hydrolyzed by true cholinesterase, which is found at the NMJ as well as at the tissues innervated by the PNS.
What would cause HR and/or BP to increase in response to Succs?
Succs stimulates nicotinic receptors at the autonomic ganglia. The succs-induced increase in HR/BP reflects the ability of succs to mimic effects of ACh at the ANS ganglia
Is there an active metabolite of Succs?
Yes. Succinylmonocholine has the same actions as the parent molecule. Succinylmonocholine is metabolized much more slowly to succinic acid and choline.
what are 11 possible complications associated with succinylcholine administration?
1. hyperkalemia, 2. bradycardia
3. Increase HR/BP, 4. Myalgia
5. Allergic rxn, 6. MH,
7. Masseter spasm
8. myoglobinuria, 9. IOP
10. Increased intragastric pressure, 11. increased ICP
List 5 conditions that may accentuate succs induced hyperkalemia?
1. Burns
2. Denervation of muscle (paraplegia)
3. Muscle trauma
4. Upper motor neuron injury (CVA, parkinson's)
5. Muscular Dystrophy
Succs is contrindicated for patients taking what eye drop medication?
Echothiophate. It depresses plasma cholinergic activity which prolongs the action of succs.
What IV dose of succs is used to treat laryngeal spasm?

If an IV site is not available, how can succs be administered?
IV dose for laryngeal spasm= 0.1-0.5 mg/kg.

If an IV site is not available, IM (deltoid) 4-6 mg/kg or SL injection may be given.
What chemical group do all muscle relaxants have in common? What is the significance of this?
All muscle relaxants have at least one quaternary ammonium group (4 carbon radicals attached to one nitrogen). Muscle relaxants are therefore ionized, lipid insoluble and highly water soluble.
Which NDMR are benzylisoquinoliniums and which are steroid derivatives?
benzylisoquinoliniums: CURIUMS - Mivacurium, atracturium, cisatracturium, doxacurium (and d-tubocurarine and metocurine)

Steroids: Curonium- vecuronium, rocuronium, pancuronium, and pipercuronium,
What law describes the displacement of NDMB from postsynaptic receptors as ACh accumulates in response to an anticholinesterase drug?
Law of mass action - which is known as Le Chatelier's Principle.
By what mechanism does pancuronium increase HR?

by what percent does pancuronium increase HR?
Competetively inhibits ACh from attaching to muscarinic receptors of the SA node.

HR increases by 10-15%
Name 2 NDMB that antagonize nicotinic receptors at autonomic ganglia and produce a corresponding decrease in SVR and BP?
d-tubocurarine and metocurine
How does rate of metabolism of mivacurium compare with that of succs?

What is the half time elimination of mivacurium?
Rate of metabolism is similar to succs.

Half time elimination of mivacurium is 2 minutes.
Name the metabolite of ester hydrolysis of atracurium that, although unlikely, can cause CNS stimulation.
Laudanosine, a lipid-soluble metabolite of atracurium, can cause CNS stimulation in high concentrations.
Which 2 NDMB have active metabolites.

Compare the activity of the metabolites with the parent compound.
Vecuronium and pancuronium have active metabolites.

the vecuronium metabolite is 50-70% as potent and the pancuronium metabolite is about 50% as potent as the parent compound.
Do patients with MG have increased or decreased sensitivity to NDMB?
Patients with MG have greatly increased sensitivity to NDMB. If possible, muscle relaxants should be avoided in patients with MG.
How does the patient with lambert-eaton myasthenic syndrome respond to NDMB? To Depolarizing MB?
Patients with Lambert-eaton are very sensitive to both NDMB and depolarizing MB. NMB should be given in small increments because of increased sensitivity.
Explain why people at high altitudes develop increased hemoglobin levels
Inspired PO2 and PaO2 are low. hypoxia stimulates erythopoietin production which acts on bone marrow to stimulate increased RBC production. Polycythemia with increased hemoglobin results
Where does the breakdown of hemoglobin occur? What are the breakdown products?
Occurs in liver. Iron and porphyrin (which is converted to bilirubin)
What is the most important determinant of blood viscosity?
The most common platelet defect is due to what?
Inhibition of platelet cyclooxygenase activity by ASA or NSAIDS
What is the significance of Factor VIII:vWF?
made in endothelial cells and is necessary for platelet ADHESION to Subendothelial sturctures when endothelial damage occurs. Also regulates production and release of factor VIII:C
What clotting factors are not plasma proteins?
Factor IV (Ca2+)
What is the function of protein C in hemostasis? What are the mechanims of protein C action?
Vitamin K dependent anticoagulant. Thrombin (IIa) activates Protein C. Activated Protein C then promotes fibinolysis by causing release of tPA from endothelial cells and by destroying plasminigen activator in hibitor. Activated protein C also cleaves factors Va and VIIa, promoting anticoagulation.
What substance breaks down fibrin, and where does this substance come from?
Plasmin digests fibrin; plasmin is formed when the plasminogen system is activated by tissue plasminogen activator (tPA)
What are five compensatory mechanisms to increase oxygen delivery in the chromic anemic patient?
1. increased cardiac output, 2. increased RBC 2,3 DPG levels, 3. increased P50 (right shift of oxyhemoglobin dissociation curve), 4. increased dissolved O2 in plasma volume, and 5. decreased blood viscosity (causes increased blood flow through tissue)
Aplastic anemia is due to what? What is the most common cause of aplastic anemia?
Lack of functioning bone marrow usually related to destruction of bone marrow stem cells by cancer chemotherapeutic drugs
megaloblastic anemia, also known as pernicious anemia, develops when there is a deficiency of either of what two substances?
lack of either vitamin B12 or folic acid, RBC fail to mature. Large, immature erythrocytes cause megaloblastic anemia
What kind of RBC result in iron deficiency anemia?
Hypochromic, micrecytic RBCs are typically found in iron deficiency anemia. When the quantity of iron in the plasma falls to very low levels, hypochromic (RBC with dimished hemoglobin) and microcytic (small, spherical RBC) anemia results
What causes hemolytic anemia?
Even though the number of RBC formed is normal, the RBC life span is so short, that serious anemia results. Causes include abnormalities in RBC membranes, enzyme defects (glucose-6-phosphate dehydrogenase deficiency), and abnormal hemoglobin (i.e.sickle cell)
What hemotological defect will you see in the patient who has a deficiency in glucose-6-phosphate dehydrogenase?
Chronic hemolytic anemia
What two drugs should be avoided in pt who has a deficiency of glucose-6-phosphate dehydrogenqase? Why?
Nitroprusside and prilocaine because these pt are vulnerable to cyanide toxicity
Which factors are most abundant in FFP? Which clotting factor is not present at all?
Factors V and VIII are most labile and are most abundant. Platelets are not present at all
Identify four general indications to administer FFP
1. isolated coagulation factor deficiencies
2. reversal of warfarin therapy
3. correction of coagulopathies associated wtih liver disease
4. after massive transfusion with continued bleeding even after platelet transfusion
What is the initial dose of FFP?
What coagulation factors are found in cryoprecipitate?
Factor VIII:C, VIII:vWF, XIII and fibrinogen (Factor I)
What may be given to treat the patient with a fibrinogen deficiency? What factor is this?
cryoprecipitate, factor I
State what fibrin split producs (FSP) assess
how fast fibrin or fibrinogen is breaking down
In what disorder is the breakdown of fibrin or fibrinogen increased?
DIC = disseminated intravascular coagulopathy
Briefly describe disseminated intravascular coagulation
an excessive (pathologic) form of fibrin breakdown (fibrinolysis) that occurs in response to increased clot formation (thrombogenesis)
Describe three specific types of DIC
Type I (secondary fibinolysis) is most common (90%) and reflects generation of thrombin and activation of plamin
Type II (consumptive coagulopahty) reflects progressin of DIC to point where plasminogen has been exhausted and uncontrolled clotting occurs
Type III (primary fibrinolysis) is exclusive activation of plasmin without concurrent thrombin formation
What four finding suggest disseminated intravascular clotting?
1. thrombocytopenia
2. prolonged prothrombin time
3. prolonged thromboplastin time
4. reduced serum concentration of fibrinogen and increased levels of fibrin split products in presence of diffuse hemorrhage
List four diseases/disorders associated with thrombocytopenia
1. Chemotherapy or unrecognized cancer,
2. Liver disease and sequestration of platelets in the spleen,
3. DIC
4. Pre-eclampsia r/t DIC
What is DDAVP? What is it used for? How does it work?
Desmopressin acetate is an analogue of arginine vasopressin (ADH). May substitute ADH to concentrate urine. May also be given to pt with vWF Type I syndrome to promote blood coagulation. Stimutes the release of vWF from endothelial cells
What is the most common cause of heparin resistance? How can this resistance be treated?
Antithrombin III deficiency. Two units of FFP are given to treat.
What three problems cand administration of protomine cause?
1. hypotension, 2. pulmonary hypertension, 3. allergic reactions all r/t histamin release
What is the protomine reversal dose for heparin? Why do you give it slowly?
1.0 to 1.3 mg of protamine is administered for every 100 units of heparin. Give over 5 minutes to decrease histamine release.
What should be done if the patient is undergoing major elective surgery is on warfarin?
D/c 1 to 3 days preoperatively to permit the prothrombin time (PT) to return within 20% of normal range.
The patient is scheduled for an orthopedic procedure on the left knee. During the preoperative workup you find that the patient has a mechanical prosthetic mitral valve and takes warfarin. What is the appropriate anesthetic plan?
For major surgical procedures in which significan blood losses may occur, it is common to discontinue warfarin 3-5 days in advance of the procedure to allow procaogulants levels to normalized. However, in a patient with mechanical prosthetic valve it is recommneded that intravenous heparin be administered following the discontinuation of warfarin up until 24 hours before surgery.
On what phase of the nodal action potential does digitalis work to slow heart rate?
Phase 4. Digitalis slows HR by slowing phase 4 depolarization of cells in the SA node and AV node.
How does digitalis work?
Digitalis binds to the sodium pump on the myocardial cell membrane and inhibits its function. This pump when inhibited causes a rise in the amount of sodium inside the heart cell, which then exchanges it for calcium through the cell membrane, as calcium rises inside the heart cell contractile mechanism becomes more optimal and stronger.
On what phase of the nodal action potential do CCB work to slow HR?
CCB such as verapamil, diltiazem, and nifedipine slow HR by slowing phase 4 depolarization of cells in the SA and AV node.
On what phase of the cardiac ventricular action potential do CCB work?
CCB (verapamil, diltiazem, nifedipine) work on phase 2 of the cardiac ventricular action potential.
What happens to the duration of the plateau with either hypocalcemia?
When hypocalcemia is present, Ca+ diffuses into the cell at a slower rate and it's accumulation in the vicinity of the K+ channel is slowed. Hence the plateau of the action potential is prolonged.
What does the QT interval reflect in relation to the phases of the cardiac cycle?

What happens to the QT interval with hypercalcemia?

With hypocalcemia?
QT interval reflects the duration of the plateau phase (phase 2).

Hypercalcemia = Short QT

Hypocalcemia = Prolonged QT
What does the T wave represent in reference to the EKG waveform?

What does peaked T waves represent?

What do U waves represent?
The T wave on the EKG is ventricular repolarization.

Peaked T waves = hyperkalemia

U waves = hypokalemia
What medications should be avoided in a patient with Wolff-Parkinson-White Syndrome (WPW)?
Digoxin and verapamil.
Avoid digoxin because it increases conduction through the accessory bypass tract (bundle of Kent) and decreases AV node conduction; VF can occur. Verapamil should also be avoided if WPW is present since it also increases conduction through the abnormal pathway.
Evidence of an evolving MI is seen in leads I, aVL, V4-V6. What region of the myocardium is involved?

What coronary artery supplies this region?
I, aVL, V4-V6 lead changes imply the lateral wall of the heart.

The lateral wall indicates the Left Circumflex is involved.
Evidence of an evolving MI is seen in leads V2 - V5. What region of the myocardium is involved?

What coronary artery supplies this region?
V2 - V5 = septum and anterior wall involvement.

Left anterior descending (LAD) is the vessel involved with V2 - V5.
Evidence of an evolving MI is seen in leads II, III, aVF. What region of the myocardium is involved?

What coronary artery supplies this region?
II, III, aVF = posterior and inferior wall involvement.

The vessel that supplies this region is the right coronary artery (RCA)
What is the best lead for detecting MI?

What is the best lead for detecting dysrhythmias?
The best lead for detecting MI = V5

The best lead for detecting dysrhythmias= II
What is the percentage of blood in the venous system?
65 - 75%
What hormone is the most important for controlling vascular volume?
Is concentric hypertrophy a pressure or volume problem?

Concentric hypertrophy develops in response to what 3 conditions?
Concentric hypertrophy = Pressure problem.

Develops in response to:
1. Untreated HTN
2. Aortic Stenosis
3. Coarctation of the aorta
Is eccentric hypertrophy a pressure or volume problem?

Eccentric hypertrophy develops in response to what 3 conditions?
Eccentric hypertrophy = Volume problem.

Eccentric hypertrophy develops in response to:
1. Chronic aortic regurgitation
2. Chronic Mitral regurgitation
3. Morbid Obesity
What law governs ventricular hypertrophy in response to pressure or volume overload?
Law of Laplace. T = P x R

TP for the Record
How many ml/min is coronary blood flow?
225-250 ml/min (4-5% of CO)
Describe the flow pattern in the left and right coronary arteries during systole and diastole....
DSuring early systole, the compression of the vasculature in the LV causes a brief cessation of flow in the LV. The flow through the RV is sustained during both systole and diastole.
What most determines coronary blood flow?
Myocardial metabolism is the major determinant of coronary blood flow.
Explain how an increase in coronary blood flow is achieved when the work of the heart increases....
Usually changes in coronary blood flow are entirely due to changes in metabolism. Local factors are produced when metabolism increases and these factors decreases coronary vascular resistance.
What 5 factors determine myocardial oxygen supply?
1. Aortic diastolic pressure (perfusion pressure)
3. HR
4. Oxygen content of arterial blood.
5. Oxygen extraction
Describe the distribution of alpha-1 and beta-2 receptors in the coronary vasculature.....What responses do these receptors mediate?
Epicardial blood vessels have mostly alpha receptors and promote VC. Intramuscular and subendocardial blood vessels have mostly beta-2 receptors which cause VD.
In the LV, where is the density of the capillaries the greatest- base, apex, subepicardium, or subendocardium?
Subendocardium. During diastole blood flow in the subendocardium is considerably grater than blood flow to the mid-wall (subepicardial). Higher blood flow refects greater O2 requirement. During systole, the subendcardium of the LV is compressed and blood flow = 0. (subendocardium is most vulnerable to ischemia)
Describe myocardial preconditioning......How much time is sufficient to achieve preconditioning? How long does the protective period last?
It is a short-term, rapid, adaptation to brief ischemia such that during a subsequent, more severe ischemic insult, myocardial necrosis is delayed. 5 minutes of ischemia is sufficient to initiate preconditioning. The protective period lasts 1-2 hours
Describe the cellular mechanisms mediating myocardial preconditioning.....
Pharmacological activation of adenosine receptors initiate preconditioning via intracellular signal transduction mechanisms involving protein kinase C, ATP dependent K channels. Other factors include Na+/H+ exchanger, inhibitory G-protien, and tyrosine kinase.
Which anesthetics agents can trigger or modulate the myocardial preconditioning response?

What can antagonize the effect?
Volatile anesthetics, adenosine, or opioid agonists agonize.

Ketamine antagonizes.
In what segment of the cardiac conduction system is the action potential conducted the fastest?

The slowest?
Purkinje = fastest

AV node = slowest
What is the function of the purkinje system?

How is this accomplished?
Purkinje system synchronizes R and L ventricular contractions. This occurs because the fibers allow rapid transmission of the impulses from the AV node to the ventricle.
Compare and contrast the PNS and the SNS innervation of the it equally innervated by both divisions of the ANS?
The SNS innervates both the atria and ventricles, and the conduction systems (SA and AV nodes). Whereas the PNS is mainly to the SA and AV nodes and the atria, with minor input to the ventricles.
Does acute hypokalemia increase or decrease excitability of nerve and cardiac muscle?
It decreases excitability- cell becomes more hyperpolarized (becomes more negative- RMP and threshold become further apart)
Does hypocalcemia increase or decrease excitability in nerves and cardiac muscle?
Hypocalcemia increases membrane excitability. The threshold potential increase (becomes more negative). Thus the resting and threshold potentials approach each other and the cell becomes more excitable.
What are the characteristics of sick sinus syndrome?

What population is this most seen in?
Bradycardia with episodes of SVT.

Most often seen in the elderly
Why is A-fib particularly dangerous in a patient with WPW?

What can result?
The refractory period of an accessory pathway determines the ventricular rate, which may exceed 300 beats/minute in a patient in A-fib with WPW. Syncope or CHF, or both can result.
The patient with WPW develops A-fib. How should it be treated?

What drugs should be avoided?
If life threatening hypotension, cardioversion is indicated. Otherwise, procainamide can be given which prolongs the refractory period. Avoid digoxin and verapamil because they may excelerate conduction through the accessory pathway.
How does procainamide work?

What class antiarrhythmic is procainamide?
Procainamide, like lidocaine, slows phase 4 depolarization, which reduces automaticity.

Class 1 A
Where is pulse pressure the greatest- Aortic root or dorsalis pedis? Why?

What principle explains this phenomenon?
Pule pressure is greatest in the dorsalis pedis. The increase in pulse pressure as the pressure wave moves peripherally is attributable to an increase in SBP and a decrease in DBP. The superimposition principle explains this phenomenon.
Which CCB causes an increase in HR?
Nifedipine (procardia) is an arterial dilator but causes a reflex increase in HR- unlike other CCB's such as diltiazem and verapamil which are both arterial dilators but decrease HR.
State whether each of the following drugs are arterial dilators, venous dilators, or both...
1. Hydralazine
2. Nitroglycerine
3. Nitroprusside
1. Hydralazine (apresoline)- arterial dilator
2. NTG - Venodilator
3. NTP - Both
Are ACE inhibitors venous or arterial dilators?
ACE inhibitors are arterial dilators.
How do Phosphodiasterase inhibitors work (PDE inhibitors)?
Inamrinone (inocor) and milrinone (Primacor) block the breakdown of cAMP, increase contractility, and decrease SVR
In critical aortic stenosis, what is the size of the aortic orifice?

What is normal aortic orifice size?

What size is associated with mild to moderate symptoms?
Critical aortic stenosis orifice size = 0.5-0.7 cm2.

Normal orifice = 2.5 - 3.5 cm2

Mild to moderate AS = 0.7 - 0.9 cm2
What is the normal size of the mitral orifice?

In mitral stenosis- how small is the orifice?
Normal Mitral orifice = 4 - 6 cm2

In Mitral stenosis, the orifice is under 2 cm2.
What type of valve is the oxygen tank on the back of the machine attached to?

What size tank?

Was is the correct position for air, oxygen, and nitrous? What is the system called?
Hanger yoke valve. The Pin Index Safety System (PISS) attaches E cylinder tanks. Any-Other-Nurse = Air-Oxygen-Nitrous (2 - 5 = Air, 3 - 5 = oxyegn, 4 - 5 = nitrous)
What is the name of the gauge that shows oxygen tank pressure?
Where is the first stage regulator located on the anesthesia machine?

What type of valve is it?
The first stage regulator takes the high cylinder pressure and decreases it to 40-50 psig. This is a diaphragm valve.
When the oxygen flush valve is engaged, how much oxygen is delivered to the patient? At what pressure?

What type of valve is it?
35- - 75 liters/minute at a pressure of 40 - 50 psig. The O2 flush valve is a ball and spring valve.
What pressure is the oxygen flow meter at? How does it get to that pressure? Are thorpe tubes gas specific? Where is the diameter the largest?
16 psig. It gets that low by the 2nd stage regulator. Thorpe tubes are gas specific with the largest diameter at the top.
Inspiration and expiration check valves are also called what?

What happens if the inspiratory valve sticks open?
Flutter valves.

If the inspiratory valve sticks open, the expiratory volume will exhaust through the inspiratory limb. The ETCO2 will become elevated.
Hemodynamic goals for a patient with valvular heart disease involve consideration of what 5 parameters?
1. HR
2. Rhythm
3. Preload
4. Afterload
5. Contractility
What is complete loss of the RAS activity called?

What is the function of the RAS?

When does RAS shut off?
Complete loss of the RAS results in Coma. The function of the RAS is to maintain an alert/awake state. The RAS serves as an indirect route by which sensory info reaches the cerebral cortex. The RAS shuts off during sleep.
What sensations are assessed by SSEP's?

What are the locations on the spinal cord where this information is located before finally reaching the cerebral cortex?
SSEP's assess: Touch, Pressure, and Vibration. (TPV)

The cuneatus and gracilis tracts of the dorsal-leminiscal system are located in the posterior (dorsal) cord. (citrus fruit looking thing!). This route to the cortex is considered the direct route.
What happens to the amplitude and the latency of SSEP's if damage has occurred in the neural pathway being monitored?
Amplitude will decrease

Latency will increase
What does Brainstem Auditory Evoked Potentials (BAEP) monitor?
BAEP, elicited by auditory clicks, is useful during operations involving CN VIII. BAEP's monitor the integrity of CN VIII.
What is Visual Evoked Potentials (VEP) useful for?
VEPS's, elicited by flashes of light, are useful if surgery is near the optic nerve. VEP's monitor the integrity of the optic nerve (CN II)
List in order the most sensitive to least sensitive evoked potentials to anesthetic agents....
1. VEP (V= Very sensitive)
2. SSEP's (S= somewhat sensitive)
3. BAEP (B= Barely sensitive)
What is the function of the dorsolateral tract?
The dorsolateral tract modulates pain
State the following dermatone landmarks:
C4, T4, T6, T10, L4-5, S2-5
C4- Clavicle
T4- Nipples
T6- Xiphoid
T10- Umbilicus
L4-5 - Tibia
S2-5 - Perineum
The Substantia Gelatinosa is also called ___________ .
The substantia gelatinosa is called rexed lamina II (some sources say lamina II and III)
Which site, epidural or spinal, is the onset of ventilatory depression faster if morphine is injected? Why?
Epidural administration of morphine will cause ventilatory depression faster (within 2 hrs) than spinal administration (6-12 hrs). Morphine is hydrophilic and crosses lipid membranes slowly but the epidural space has greater systemic uptake than the spinal space.
Compare hydrophilic and lipophilic opioids with regard to speed of onset and duration of action after epidural or spinal placement.
Compared with lipophilic opioids (fentanyl), hydrophilic opioids (morphine) have a slower onset and a longer duration after injection in either the epidural or spinal space.
What is the dominant receptor mediating spinal analgesia?
Mu-2 is dominant. Mu -1, Kappa, and delta also play a role. Spinal analgesia occurs when transmission of pain impulses through the substantia gelatinosa (rexed Lamina II) is suppressed.
What is the dominant pain receptor mediating suprspinal analgesia?
Mu - 1 is dominant. Kappa and delta receptors also play a role. With supraspinal analgesia, the patient's response to pain is altered (IV opioid administration)
Preganglionic sympathetic nerves arise from the ____________ .
Intermediolateral horn of the SC
Major inhibitor neurotransmitter in the spinal cord?
Where is the epidural space located in relation to ligamentum flavum: anterior, posterior, superior or lateral?
Anterior to the ligamentum flavum
What is epidural space filled with?
The epidural space is filled with loose connective tissue that surrounds epidural veins and spinal nerve roots (M&M) Epidural space is filled with adipose blood vessels and lymphatics (E&F)
The epidural space between ligamentum flavum and dura mater is largest at what level?
L2-L3--- approximately 4-6 mm
The potential space between dura mater and arachnoid mater is -------?
Subdural Space
This space lies between arachnoid and pia maters. It is filled with CSF?
Subarachnoid space
What structures of anesthetic importance run in the subarachnoid space?
Spinal nerves and rootlets
How many spinal nerves do we have?
31 (C-8, T-12, L-5, S-5, C-1)
What is another name for C1 and C2 vertebrae?
C1-atlas, C2- axis
Where does spinal cord end in the adult and neonate?
L1-adult, L3-neonate
The largest space in the spinal canal is found where?
L5- 27 mm, L1- 22 mm,
What are the anterior and posterior longitudinal ligaments (ALL and PLL)?
ALL- runs along the anterior longitudinal bodies from C2 to the upper sacrum. Strong and robust throughout
PLL- extends along the posterior surface of the vertebral bodies. Becomes thin and narrow in the lumbar region. This is why majority of disc herniations occur posteriorly in the lumbar region
Which nerve controls the medial rectus muscle of the eye? This will cause the eye to do what?

What CN controls lateral rectus muscle of the eye? Stimulation of this nerve cause the eye to do what?
Medial Rectus = CN III- Adduct

Lateral Rectus = CN VI-Abduct
What nerve stimulates the sneeze reflex?

Which cranial nerve provide sensory innervation of the face? What are the branches?
CN V (Trigeminal Nerve) - Branches are:
1. Opthalmic (Sensory)
2. Maxillary (Sensory)
3. Mandibular (Sensory and Motor)
How can damage to CN XII (hypoglossal nerve) affect the airway?
Controls ext and int muscle of tongue. Damage to this will cause the tongue to relax- causing it to fall back and obstruct the airway
In addition to the respiratory and cardiovascular centers, what other centers are found in the brainstem of medulla?
Vomiting ,coughing and swallowing.
Site of Formation of CSF?

Site of Reabsorption of CSF
Formed in choroid plexus of lateral (most formed), third and Fourth Ventricle

Reabsorbed in the Arachnoid Villi
What is total normal CSF production?

What is the total normal CSF volume at a given time?
500 ml/day or 21 ml/hr or .35 ml/min.

Total Volume = 130-150 ml.
Name the connection between the third and fourth ventricle?
Aqueduct of Sylvius
Where is the most common site of obstruction leading to hydrocephalus?
Cerebral Aqueduct
What is Blood Brain Barrier (BBB) and its function?
BBB are tightly connected endothelial cell (podocytes) of cerebral capillaries. It serves to protect the brain from sudden changes in plasma composition such as hyper K, acute alkalosis or acidosis and increased catecholamines.
What substances do not diffuse across Blood Brain Barrier ?
Ions (Na, Ca, Mg, K), polar molecules (AA, glucose, mannitol) water soluble drugs and proteins
What substances cross the Blood Brain Barrier?
Lipid soluble compounds (IV and VA) water and gases (O2,CO2)
What four factors determine how much of a substance will diffuse across the blood brain barrier?
1. Size
2. Charge
3. Lipid solubiity
4. degree of protein binding
What regions of the brain have no blood brain barrier?
Chemoreceptor trigger zone (CRTZ), capillaries of the choroid plexus and area around posterior pituitary
Glucose is used by the brain at a rate of _________ .
5 mg/100g/min
What is cerebral metabolic rate (CMR)?
3 - 4 ml/100g/min
CMR decreases/increases by how much with changes in temperature?
6-7 % for each 1 degree C in temperature
What are the major vessels supplying Circle of Willis?
Right and Left Internal Carotids and Basilar artery. Basilar artery is supplied by Right and Left Vertebral arteries
What is Autonomic Dyseflexia (AD)?

What triggers it?

Transection of the spinal cord above what level is most likely to lead to episodes of AD?
AD results from reflex stimulation of the sympathetic preganglionic neurons arising in the anterolateral column of the spinal cord below the level of a SC lesion.

Stimulation of distended bladder and bowel can trigger AD. Skin breakdown, UTI, pain, or surgical stimulation below the lesion. The lesion at T5 or T6 is most likely to lead to episodes of AD.
What is the typical time-frame for onset of AD following SC injury?
AD usually follows a period of spinal shock that typically last 1-3 weeks. Onset of AD may occur at any time from few months to many years after initial injury.
What percent of patients with complete spinal cord transection above T5 exhibit autonomic hyperreflexia?
How does surgical stimulaton cause hyperreflexia in the pt with spinal cord injury?
Loss of supraspinal inhibitory influences causes hyperreflexia during surgical stimulation. The sensory input from dermatomes below the injury are unrestrained by feedback from the higher centers
What anesthetic techniques is effective for preventing Autonomic Dysreflexia?
Spinal anesthesia
Describe the sensory innervation of the facial nerve?
The facial nerve (CN VII) provides special sensory innervation to the anterior 2/3 of the tongue (taste) and general sensory innervation to the tympanic membrane, external auditory meatus, soft palate, and part of the pharynx.
Name the cranial nerve controlling equilibrium.
The vestibular branch of cranial nerve VIII controls equilibrium.
In an EEG, what type of waves occur during surgical anesthesia?
Delta waves occur during deep anesthesia
What are the cardivascular actions of glucagone? What second messenger is involved in these responses?
Increased myocardial contractility (+ inotropic effect) and heart rate. Increase CO. Increases intracellular levels of cyclic AMP by mechanisms independent of beta-adrenergic receptor stimulation
List three cardiac effects of digitalis
1. enhances myocardial contractility 2. decreases HR 3. slows impluse propagation through the AV node (enhances parasympathetic nervous system activity).
Why is verapamil a poor choice when treating a patient with Wolff-Parkinson-White Syndrome?
May increase conduction velocity in the accessory tract and increase HR excessively.
Why shoul.d verapamil be avoided or used cautiously in patients taking either a beta-blocker or digitalis?
Verapamil and beta blockers or digitalis can produce complete heart block
What are the cardiovascular actions of diltiazem?
Good coronary vasodilator but a poor peripheral vasolitator. Also decreases HR
How does nifedipine affect systemic vascular resistance and HR?
Decreases SVR and causes refex bradycardia
Name four vasodilators that decrease blood pressure by direct effects on vascular smooth muscle indepentent of alpha or beta receptors
1. Hydralazine (arterial)
2. Nitroprusside (arterial and venous)
3. Nitroglycerine (venous)
4. Diazoxide (arterial)
What are four contraindications for using sodium nitroprusside?
1. patients with liver disease 2. kidney disease 3. hypothyroidism 4. vitamin B-12 deficiency
How is cyanide produced r/t nitroprusside use?
With high doses of nitroprusside the ferrous iron of nitroprusside reacts with sulfhydryl groups in red blood cells and relseases cyanide.
Sodium nitroprusside contains five cyanide ions and may cause cyanide toxicity, as you know. What three reactions may cyanide ions undergo?
1. binding to methemoglobin to form cyanomethemoglobin 2 reaction with thiosulfate in the liver to produce thiocyanates, catalyzed by rhodanase and 3. binding to tissue cytochrome oxidate, which interferes with normal oxygen utilization by tissues
List the four hallmark signs and symptoms of cyaninde toxicity
1. metabolic acidosis (base deficit) 2. cardiac arrhythmias 3. increased venous ocygen content d/t inhibition of cytochrome oxidase and consequent inabilty of cells to utilize oxygen 4. tachyphylaxis
What is the best indicator of cyanide toxicity?
Base deficit. the metabolic acidosis accompanying cyanide toxicity allows the observant practitioner to detect this cellular toxicity. Arterial blood gases permit determination of the base deficit and hence may most accurately assess cyanide toxicity
The patient shows evidence of cyanide toxicity. you d/c'd nipride and have given thiosulfate. Pt remains unstable and metabolic acidosis continues. What is your next step? Why?
Slow administration of sodium nitrate (5mg/kg IV). It converts hemoglobin to methemoglobin. Alternatively, hydroxocobalamin (Vitamin B-12), which binds cyanide to form cyanocobalamin cand be administered (25 mg per hour IV to max of 100mg) to treat the toxicity
What are the signs of digitalis toxicity?
1 atrial or ventricular cardiac dysrhythmias 2 prolonged PR interval, 3. GI disturbances (anorexia, N/V).
What three electrolyte disturbances enhance digitalis toxicity?
hypokalemia, hypercalcemia, hypomagnesium
In what phase of the cardiac cycle does digitalis work to slow the heart rate?
phase 4. It decreases automaticity and lowers HR. Automaticity is relfected in the slope of phase four depolarization. Does so by activating the PNS
Why does hypokalemia enhance digitalis toxicity?
Allows increased binding of digitalis to Na+ K+ ATPase pump in cardiac cells, resulting in an excessive drug effect
What are five uses of calcium entry blockers?
1. supraventricular tachydysrhythmias (verapamil)
2. essential hypertension
3. coronary artery vasospasm (nifedipine and diltiazem)
4. angina pectoris
5. cerebral artery vasospasm (nimodipine)
Where in the vascular tree does diazoxide work? How is it used? What is the disadvantage?
Arterial vessels more then venous thus decreasing afterload. (1-5mg IV bolus) is used to treat HTN emergencies. No possible to titrate BP to a given level of diazoxide.
What syndrome occurs in 10-20% of patients treated chronically with hydralazine? Are these patients fast or slow acetylators?
A systemic lupus-erythematosus-like syndrome when treated >6 months. Occur in slow acetylators. Syndrome disappears when drug d/c'd
What are class I cardiac antidysrhythmic drugs? Identify class IA drugs, class IB drugs and class IC drugs and specify how each group works?
Class I antidysrhythmic drugs are MEMBRANE STABALIZERS that work by inhibiting sodium ion channels (block sodium channels). Class IA drugs include quinidine and procainamide. Class IB drugs include lidocaine, tocainide and phenytoin and class IC drugs include flecainide and propafenone.
Class I antidysrhythmics are used to treat what three conditions?
Acute and chronic supraventricular dysrhythmias, to slow atrial rate in atrial fibrillation and to suppress tachydysrhythmias in WPW syndrome
What drugs are class II antidysrhythmics and what do they do?
Class II antidysrhythmics are beta-adrenergic antagonists. Depress automaticity (decrease HR by spontaneous phase 4 depolariztion in nodal tissues) and decrease conduction speed of cardiac impulses.
What durgs are class III cardiac dysrhythmic drugs and what do they do?
Prolong repolarization by blocking voltage-gated potassium channels. Amiodarone, ibutilide, dofetilide and bretylium (no longer recommended) are class III. These drugs prolong the effective refractory period in the SA and AV nodes, atria, and ventricles and His-Pirkinje fibers
What drugs are clas IV cardiac dysrhythmias and what are they used to treat?
Slow calcium channel blockers including verapamil and diltiazem. Treat paroxysmal SVT and effectively control ventricular ratee in pts who dev AFib or flutter
What four drugs should be avoided in patients being treated with digtalis?
1. quinidine, which increase the plasma concentration of cardia glycosides 2. succinylcholine, which increase the parasympathetic activity in the heart and may theoretically have an additive effect with cadiac glycosides 3. beta blockers, which may increase the likelihood of cardiac dysrhythmias and 4. IV calcium which may precipitate cardiac dysrhythmias
What is your concern giving phenytoin to the hyperglycemic patient?
It partially inhibits insulin release and may lead to increased blood glucose levels in patient with hyperglycemia.
Describe the metabolism and elimination of adenosine (adenocard)
rapidly eliminated by enzymatic clearance (less then one minute). It is deaminated in the plasma forming inosine, or is taken up in erythrocytes (RBCs) and vascular endothelial cells where it is metabolized to inosine (by deamination) or adenosine monophophaste (by phosphorylation)
List five components of the circle system.
1. gas resevoir bag
2. two corregated tubes
3. two unidirectional valves
4. canister containing a CO2 absorbent
5. an overflow valved to permit escate of excess gases
What is the most common site for breathing circuit disconection?
although disconnection can occur anywhere in the breathing system, the most common site is between the breathing system and the tracheal connector or heat-moisture exchanger.
What is the treatment of choice for autonomic hyperreflexia during surgery?
The treatment of choice is removal of causative stimulus. Other actions that maybe instituted include deepening of anesthesia and if necessary administering direct acting vasodilator such as Sodium Nitroprusside.
What is Cushing’s Triad?
reflex increase in mean arterial BP, reflex decrease in HR, irregular respiration- in response to increased ICP. May be a sign of impending herniation.
What are the components of intracranial volume?
Brain (water)-80%,
What keeps ICP from increasing initially when one of the intracranial compartments begins expanding because of pathological condition?
CSF passes through the foramen magnum into the spinal cord (displacement). Also decreased CSF production and decreased CBF.
Name 3 components of ICP waveform and indicate which two are not useful in guiding therapy or predicting outcome?
A wave (plateau), B and C waves. A waveform is found in patients with elevated ICP. B and C waves are lesser magnitude and r/t resp pattern and BP, not useful in guiding therapy.
What are the 12 signs and symptoms of increased ICP?
headache / nausea / vomiting
-blurred vision
-unilateral pupillary dilation (anisocoria)
-CN III palsy (occulomotor) unable to adduct eyes
-CN VI palsy (abducens) unable to abduct eyes
-Irregular respirations
-Altered LOC(somnolence/unconsciousness)-Seizures
What eight steps can the anesthetist take to treat an increase in ICP?
-Mannitol (.25-1 g/kg)
-Furosemide (0.5-1mg/kg)
-Corticosteroids-localized cerebral edema
-Hyperventilation- PaCO2 of 25-30 mm Hg
-Restrict fluids
-30 degree head elevation-venous drainage
-Administer potent cerebral vasoconstrictor such as thiopental, etomidate, or propofol
-Control BP
- Cool the patient to 34 degree centigrade to protect the brain during surgery.
What is the preferred drug to reduce brain swelling?
What dose?
MANNITOL - (0.25 - 1.0 grams/kg)
What is the mainstay therapy of acute and subacute management on increased ICP?
Hyperventilation -PaCO2 25-30.
Is the decrease in Cerbral Vascular Resistence (CVR) and CBF associated with acute hyperventilation and hypocapnia sustained during chronic hyperventilation to treat increased ICP?
No. CVR and CBF normalizes after 6 hours.
What agents are suitable for induction if a patient has high ICP?
Agents that constricts cerebral vasculature thereby decreasing CBF and ICP such as barbiturates, etomidate and propofol.
What IV anesthetics would you not administer to a patient with an elevated ICP and Why?
Ketamine increases CBF and ICP
What fluid should not be used on a patient with elevated ICP and cerebral injury? Why?
D5W or any other dextrose containing solution should be avoided. Hyperglycemia has been shown to exaggerate neurological deficits after incomplete neurological ischemia.
When the seizure threshold increases, is the pt. more likely or less likely to have seizure? What if the seizure threshold decreases?
When the seizure threshold increases, the pt. is less likely to have seizure. Conversely when the seizure threshold decreases the pt. more likely to have seizure.
How does alkalosis alter seizure threshold?
Decreases seizure threshold. With alkalosis cerebral vessels constricts and cerebral blood flow decreases which subsequently decrease oxygen and glucose delivery.
How does acidosis alter the seizure threshold?
Increases seizure threshold. It is increased because acidosis causes cerebral vasodilation which increases cerebral blood flow and oxygen delivery to hypoxic regions of the brains.
The threshold of seizure activity is increased when the anesthetist gives what drugs?
Potent inhaled anesthetic agents desflurane and isolurane produce dose dependent depression of EEG activity. Barbiturate and Benzodiazepines increase the seizure threshold Propofol has been shown to increase seizure threshold, even more than thiopental.
What four electrolyte disorders lower the seizure threshold and predispose the patient to seizures?
Hypocalcemia, hypomagnesemia, hyponatremia (TURP syndrome), and hypernatremia
List drugs that may decrease seizure threhold when therapeutic doses are administered to non-epileptic patient.
TCA, antipsychotics, CNS stimulant, hypoglycemic agents, aminophylline, antihistamines, ephedrine, enflurane, etomidate, ketamine, metohexital, opiods (meperidine) and steroids.
Administration of what opioid is most likely to produce seizure? Why?
Meperidine may cause seizures, because it is metabolized rapidly to the CNS stimulant, NORMEPERIDINE, which possesses twice the convulsive activity of meperidine
Which of the following condition increases the seizure threshold: Hypokalemia, hyperkalemia, hypocalcemia, alkalosis or acidosis?
Somatic sensory neurons are

A. efferent & enter the cord via the ventral horn
B. efferent & enter the cord via the dorsal horn
C. afferent & enter the cord via the ventral horn
D. afferent & enter the cord via the dorsal horn
D. Afferent & enter the cord via dorsal horn
Which of the following evoked potentials is most sensitive to

a. Visual evoked potential
b. Somatosensory evoked potential
c. Brainstem auditory evoked potential
A. Visual Evoked potential
What substance decreases the release of Substance P in the spinal cord?
Mu-2 receptors cause:
Respiratory depression & physical dependence
Lipid Solubility = potency
Whose theory?
Meyer Overton
Solubility of gas in liquid decreases as temperature increases.
Whose law?
Gas bubbles distend when N2O is turned on.
Whose law?
Fick’s law of diffusion
How long will it take to read 1.2% Isoflurane at the end of the circuit?
Four time constants or 56 minutes.
Which IV anesthetics are compatible with SSEP?
STP - barbiturates
In which of the following situations would you NOT want to use an LMA? Pick all that apply
A. Abdominal surgery
B. Patient with pulmonary fibrosis
C. BMI of 30-35 kg/m2
D. > 14 weeks pregnant
E. Peak airway pressures > 20cm H20
F. Opiate usage prior
Answer: B, D, E, F
What size LMA would you use for a 70kg patient? What is the maximum cuff volume? What size would you use if the one you need is unavailable?
A. 3, 20ml, 3.5
B. 4, 25ml, 5
C. 4, 30 ml, 5
D. 5, 40ml, 4
E. 5, 40ml, 6
Answer: C
You have inserted a swan ganz catheter in the right internal jugular vein. At what cm markings will you reach the right atrium, right ventricle, and pulmonary artery?
RA- 20cm
RV- 30 cm
PA- 45 cm
State the hemodynamic goals for a patient with Mitral Stenosis.
Slow rate
Regular (sinus)
Not too full (maintain preload)
Not too tight (maintain SVR)
Not too strong (Maintain contractility)
State the hemodynamic goals for a patient with aortic insufficiency (regurg).
Fast rate
Regular rhythym
Full (increase preload)
Forward (decrease afterload/SVR)
Not too strong (maintain contractility)
State the hemodynamic goals for a patient with Mitral Insufficiency (regurg).
Maintain or increase HR (avoid Brady)
Regular rhythm (sinus)
Decrease afterload/SVR
maintain or increase preload
Maintain or increase contractility.
Are the hemodynamic goals for Aortic regurg and mitral regurg similar?
Yes. Maintain HR (or increase, and decrease SVR, maintain preload (or increase)
What 4 changes increase the outflow obstruction in a patient with IHSS?
1. Increased contractility
2. Increased HR
3. Decreased preload
4. Decreased afterload
What is the first line treatment for hypotension in the patient with IHSS?

What is 2nd line treatment?
1. Volume is 1st line treatment.

2. 2nd line is alpha agrenergic VC - Phenylephrine
What drugs should be avoided in a patient with IHSS?
Vasodilators (NTG, NTP)
Positive inotropes (digitalis, Ca+)
beta agonists
All these agents can worsen the outflow obstruction
What is the most ominous sign of Coronary artery disease?

What is the primary goals of anesthesia in the patient with CAD? Which is most important?
1. Unstable angina is most ominous (angina at rest)

2. Goal is to maintain CV stability - avoid hypotension/hypertension, and tachycardia. Avoid increase in HR is most important due to increased myocardial metabolism.
What is the incidence of peri-operative reinfarction for non-cardiac surgery at:
0-3 months?
4-6 months?
After 6 months?
0-3 months = 27-37%
3-6 months = 11-16%
Over 6 months = 5-6%
Elective surgery is best not performed until after how much time has elapsed after a MI? Why?
6 months. Reinfarction will occur within 1 week of anesthesia with non-cardiac surgery in 5-6% of patients. Before 6 months- the risk is much greater.
What are 3 signs of poor RV function?
1. Systemic venous congestion
2. Peripheral Edema
3. Congestive hepatomegaly.

Pulsating neck veins indicate venous congestion secondary to right-sided heart failure.
What Pulmonary Capillary Wedge pressure is indicative of heart failure?
PCWP greater than 18 mmHg is indicative of heart failure.
What are 5 compensatory responses in a patient with cardiac failure?
1. Increased LV preload
2. Increased sympathetic tone
3. Activation of the RAAS
4. Release of AVP
5. Ventricular hypertrophy
With CHF, what hormonal system is activated as a compensatory mechanism? What are the changes made by the activation of this hormone system?
In response to CHF, the RAAS and sympathetic system are activated. Both contribute to the progressive structural changes in the peripheral vasculature and in the remodeling of the LV.
What is cardiac tamponade?

Is the hypotension associated with cardiac tamponade due to changes in preload, afterload, or contractility?
Cardiac tamponade is accumulation of fluid in the pericardial space causing increased external intracardiac pressure and decreased ventricular filling (preload). SV and BP decrease due to decrease in preload.
What is Beck's Triad?
Beck's Triad are signs of cardiac tamponade.
1. Hypotension
2. JVD
3. Muffled heart sounds
What happens to arterial BP during inspiration in a patient with cardiac tamponade? What is this called?
Normally, SBP decreases 6 mmHg or less during inspiration. A prominent decrease (over 10 mmHg) is SBP occurs during inspiration with cardiac tamponade. It is called Pulsus Paradoxus.
What are 3 temporary measures that can be taken to maintain SV in a patient with cardiac tamponade?

What is definitive treatment?
1. Fluids (maintain ventricular filling)
2. Positive inotrope (beta-1 agonist) to increase contractility.
3. Correct metabolic acidosis

Tx = Pericardiocentesis
Which cardiac pressure equalize during cardiac tamponade?

What is the pressure they equalize to?
R and L Atrial pressures and RVEDP equalize at about 20 mmHg
A patient with cardiac tamponade needs to be induced. what agent should be selected?
Ketamine (0.5 mg/kg) and 100% oxygen after decompression of the pericardial space. (page 22 in MM or kaplan cardiac anesthesia P. 935)
What percentage of hypertensive patients become hypertensive upon intubation? What is the goal when anesthetizing the medically controlled hypertensive patient?
20-25% of hypertensive patients become hypertensive upon intubation. The goal is to maintain BP within 20-30% of the patients usual BP.
What is another name for Takayasu's Arteritis? What is the underlying disease process? What part of the population is primarily affected?
Takayasu's arteritis is also called pulseless disease because of the absence of palpable peripheral pulses. Chronic inflammation of the aorta and it's major branches is the cause. Primarily affects young asian females.
Of the following neuron morphologies, which is the most common in the human nervous system? unipolar, pseudo-polar, or multi-polar?
Multi-polar is the most common.
What 2 properties of neuronal tissues enable them to respond to stimuli?
1. Presence of a RMP
2. Presence of VG Na+ channels
What is the major cation outside the neuron? Inside?
Outside = sodium (142 mM)

Inside = potassium (140 mM)
Describe absolute refractory period. In what state are the VG Na+ channels during absolute refractory period?
The absolute refractory period is the time period following stimulation of an excitable tissue during which no additional action potentials can be evoked. VG Na+ channels are closed in the inactivated state.
What are 3 common inotropic glutamate receptors in the CNS?

Which ions pass through these receptors upon activation?
3. Kainate

Na+, Ca+, K+
What enzyme catalyzes the synthesis of ACh? Where does ACh synthesis occur? What breaks down ACh? What does ACh breakdown to?
ACh synthesis occurs in the cytoplasm of nerve terminals. Choline acetyltransferase (ChAT) catalyzes the formation of ACh from precursors Choline and Acetyl-CoA. ACh is broken down by acetylcholinesterase into choline and acetate.
Explain how and where MAO works.

Explain how and where COMT works.
MAO - metabolises amines within the terminals of nerves (NE, Dopamine, Seritonin).

COMT - degrades NE and Epi primarily as they circulate through the liver.
The GABA type A receptor has at least 7 ligand binding sites. What are the sites?
2. Barbituates
3. Benzos
4. Propofol
5. Steroids
6. Anesthetic/alcohol
7. Picrotoxin
What is the conus medullaris?

What is the filum termiale?
Conus meddularis is the blunt, tapering tip of the SC. The pia alone continues from the conus medullaris and after peircing the dural sac, continues witha covering of dura to the coccyx, forming the filum terminalis. The filum terminalis is comprised of pia and dura matter.
In the supine patient, the highest point of the spinal column lies at which vertebra? Where is the lowest?
Highest = L3

Lowest = T6
What 2 sympathetic ganglia form the stellate ganglia? How frequently are the anatomical components of the stellate ganglia fused?
Together, the inferior cervical ganglion and the first thoracic ganglion form the stellate ganglia. In 80% of the population they are fused.
Identify the only endogenous compound that causes simultaneous bradycardia and hypotension?
Identify 2 forms of MAO. Which substances are metabolized by each form of this enzyme?
MAO Type A - Metabolizes serotonin, dopamine, Epi, NE

MAO Type B - metabolizes dopamine, tyramine (found in red wine, cheeses, beer) and phenylethylamine. Doapmine is metabolised by both A and B.
Identify 6 orbital muscles, their function, and motor innervation.
1. Superior rectus -look up- CN III
2. Inferior rectus-look down-CN III
3. Medial rectus-Look in- CN III
4. Lateral rectus-Look out-CN VI
5. Superior oblique-look in and down- CN IV
6. Inferior oblique-look out and up - CN III
what is cerebral BF in ml/min? % of CO? and in ml/100g/min?

Below what CBF does cerebral ischemia occur?
CBF = 750 ml/min, 15% of CO, and 50 ml/100g/min

EEG evidence of cerebral ischemia appeard when CBF has fallen to 50% of normal (375 ml/min, 7.5% of CO, and 25 ml/100g/min)
What are the 2 determinants of CBF?
cerebral vascular resistance and Cerebral BF. CBF is inversly proportional to CVR and directly proportional to CPP.

Identify 3 factors that alter CVR and hence CBF.
1. PaCO2
2. PaO2
3. Temperature
The single most important determinant of CBF is what?
PaCO2. CBF is proportional to PaCO2 when PaCO2 varies between 20-80 mmHg. CBF changes 1-2 ml/100g/min per 1 mmHg change in PaCO2.
What is the only IV anesthetic agent that dilates cerebral vasculature? How much does this agent increase CBF?
Ketamine dilates cerebral vasculature and increases CBF by 50-60%.
How much does CBF decrease for each 1 degree C decrease in temperature?
CBF decreases 5-7% for each 1 degree C decrease in temperature.
For each 1 degree C decrease in temperature, CMR decreases by what %?
cerebral metabolic rate decreases by 6-7% for each 1 degree C decrease in temperature.
Does acute metabolic acidosis or alkalosis alter CBF?
No. Alterations in CVR occur when the pH of the CSF is altered (which occurs quickly with changes in PaCO2). Since ions including H+ and HCO3- do not cross the BBB, neither acute metabolic acidosis nor acute metabolic alkalosis alters CBF.
When PaO2 falls below what level will CBF increase?
CBF will increase substantially when PaO2 falls below 50 mmHg.
At what ICP does focal ischemia occur?

At what ICP does global ischemia occur?
Focal ischemia - Occurs when ICP= 25-55 mmHg.

Global ischemia - occurs when ICP exceeds 55 mmHg
How is cerebral steal syndrome triggered during anesthesia?
cerebral steal, AKA luxury perfusion, can be triggered if a VD is given (NTG, NTP, Hydralazine) or if the patient is hypoventilated. In hypoventilation, PaCO2 increases, pH decreases, arterioles in non-ischemic brain dilate, and BF to non-ischemic brain increases. This vasodilation in non-ischemic brain tissue could theoretically result in steal of blood from the ischemic areas that require O2.
What % of intracranial volume is occupied by brain? By blood? and by CSF?
Brain = 80%
Blood = 12%
CSF = 8%
What keeps ICP from increasing initially when one of the intracranial compartments begins expanding due to a pathological condition?
CSF passes through the foramen Magnus into the SC.
What is papilledema?

What causes it?

Which cranial nerve is involved?
Papilledema is edema and hyperemia of the optic disk. It is associated with increases ICP. It involves CN II (optic nerve).
The anterior, middle, and posterior cranial fossa contain what structures? What herniates with excessive ICP's and where does it herniate?
The frontal lobe rests on the anterior cranial fossa. The temporal lobe rests on the middle cranial fossa. The brainstem and cerebellum rest on the posterior fossa. The brain stem herniates through the foramen magnum with excessive ICP.
12 signs of increased ICP...
1. HA; 2. N/V; 3. Blurred vision; 4. Unilateral pupil dilation; 5. papilledema; 6. CN III paralysis (can't adduct eye); 7. CN VI paralysis (can't abduct eye); 8. hypertension; 9. bradycardia; 10. irregular respirations; 11. altered LOC; 12. Seizures.
What is Cushing's Triad?

What does it mean?
1. Bradycardia
2. Hypertension
3. Irregular respirations

Indicative of elevated ICP and impending herniation.
What are 8 steps the anesthetist can take to treat elevated ICP?
1. Dehydrate the brain with mannitol (0.25-1 mg/kg) and lasix (0.5-1 mg/kg); 2. Cortocosteroid (decadron); 3. hyperventilate; 4. restrict IVF; 5. Elevate head to over 30 degrees; 6. potent cerebral VC such as propofol, etomidate, thiopental; 7. Control BP; 8. cool patient to 34 degrees C to protect brain.
Dexamethasone, Furosemide, hyperventilation, and mannitol are common therapies to decrease ICP. Rank these from fastest to slowest response time and duration.
1. Hyperventilation- immediate onset and lasts 4-6 hours.
2. Mannitol- acts with 10-15 min and lasts 2 hours.
3. Furosemide acts within 30 minutes, less effective than mannitol.
4. Corticosteroids may require hours to days before decrease in ICP is apparent- but they may restore the BBB.
List 9 adverse effects of mannitol.
1. Pulmonary edema; 2. Rebound increase in ICP; 3. Hypovolemia; 4. hypernatremia; 5. Hyponatremia (yes-both); 6. Hyperkalemia; 7. acidosis; 8. Dehydration; 9. Acute hemodilution.
Will mannitol alter serum glucose levels? Why or why not?
No. Mannitol is an inert 6-carbon sugar that is neither metabolized nor converted, so it should not alter blood glucose levels.
Define specific gravity. Is specific gravity of body fluids less than one or greater than 1?

What is the specific gravity of CSF?
Specific gravity is the weight of one ml of a sample divided by the weight of 1 ml of H2O. Most body fluids contain solutes (ions/proteins) and therefore have specific gravities over one. The specific gravity of CSF = 1.003 - 1.008.
A patient has a fracture at T1. At the time of injury, what happens to BP and HR?
This is acute spinal shock. Hypotension develops becasue sympathetic outflow to blood vessels ceases. Blood vessels dilate causing the decrease in BP. Since cardiac accelerator fibers are involved (T1-T4), bradycardia occurs. Other s/s of spinal shock will be a decrease in SVR, atient will feel warm and dry, hypovolemia due to venodilation, and hypothermia.
List 4 efferent responses that develope after the acute phase of spinal shock. can surgical stimulation trigger these responses?
1. Motor hyperreflexia (muscle rigidity/spasm)
2. Flexor responses (initiated by pain, bladder distention, surgery)
3. Late return of extensor reflexes
4. Autonomic hyperreflexia
In autonomic hyperreflexia, why is there VC below the block and VD above the block? What happens to HR?
Massive reflex sympathetic discharge (autonomic hyperreflexia) cause intense vasoconstriction below the level of cord damage. Blood pressure increases. The baroreceptor reflex is activated, which leads to reflex vasodilation above the level of cord injury. Bradycardia is reflexly mediated.
What cranial nerve innervates the posterior 1/3 of the tongue?

Which innervates the anterior 1/3 of the tongue?
posterior 1/3 = Glossopharyngeal (CN IX)

Anterior 2/3 = Facial Nerve (CN VII)
What muscle acts as a barrier to regurgitation in the conscious patient?
In the awake patient, the cricopharyngeus is the primary muscular barrier to regurgitation.
List the 9 laryngeal cartilages in order from superior to inferior.
Recall 3 are paired and 3 are unpaired. Superior to inferior: Epiglottis, Thyroid, cuneiform (paired), corniculate (paired), Arytenoids (paired), and cricoid.
What the muscles that abduct and adduct the vocal cords?

What muscles tense the vocal cords? What muscles relax the vocal cords?
Abduct = Open = Dilate = Posterior Cricoarytenoids.

Adduct = Close = Constrict = Lateral Cricoarytenoids.

Tense = legnthens =Cricothyroid

Relax = Thyroarytenoids
What nerve provides sensation above the vocal cords?

What nerve provides sensation below the vocal cords?
Above cords = Internal branch of the SLN (part of vagus)

Below cords = Recurrent laryngeal nerve (also part of the vagus)
Laryngealspasm is caused by stimulation of which nerve?

What muscles are involved in laryngealspasm?
Stimulation of the external branch of the SLN may cause laryngealspasm.

Muscle involved in laryngealspasm are the cricothyroid muscles (adduct and tense).
The diaphragm is innervated by what nerve? Arising from what segments of the spinal cord?
Phrenic nerve. Arises from C3, C4, C5. The phrenic nerve arises chiefly from the 4th cervical nerve.
Define dead space.
Define anatomic dead space.
Define alveolar dead space.
Define physiologic dead space.
Dead space -portion of tidal volume that does not participate in gas exchange.
Anatomic dead space- volume of air in the conducting airways (no gas exchange) = 2 ml/kg
Alveolar dead space- volume of inhaled gas that enters non-perfused or poorly perfused alveoli.
Physiologic dead space - Sum of the anatomic and alveolar dead space.
What percentage of TV in a spontaneously breathing adult is dead space? In a paralyzed and ventilated patient?
Spontaneously breathing patient, dead space = 20-40% (33%) of TV and 40-60% in a paralyzed and ventilated patient.
What site in the trachea produces the strongest cough reflex?

What respiratory cells secrete mucus?

What cells secrete surfactant?
Carina = cough

Goblet cells produce mucus

Type II alveolar epithelial cells secrete surfactant
Define Compliance.

Define Resistance.
Compliance = The change in volume that occurs in response to a change in pressure.

Resistance = the change in pressure along a tube divided by flow.
What are 3 primary functions of surfactant?
1. Acts like a detergent to decrease surface tension so pulmonary compliance is increased and work of breathing is decreased.
2. Permits alveolar stability by keeping small alveoli from collapsing into large alveoli.
3. Helps keep alveoli dry.
What is the cause of exhalation during the normal respiratory cycle?
Passive recoil of the lungs is responsible for exhalation during normal tidal breathing.
What happens to intrapulmonary pressure during normal inspiration? During exhalation?

When is intrapleural pressure positive during a normal respiratory cycle?
Intrapulmonary pressures become negative (sub-atmospheric) during inspiration and become positve during exhalation.

Intrapleural pressure is NEVER negative during normal breathing (more negative during inspiration and less negative during exhalation).
Residual volume is what percent of TLC?
RV = 20 - 25% of TLC
How is minute ventilation (MV) calculated?

How is minute alveolar ventilation (MAV) calculated?
MV = RR x TV

MAV = RR X (TV - anatomic dead space [2 ml/kg])
Are PaCO2 and ETCO2 directly or inversely proportional to alveolar ventilation?
PaCO2 and ETCO2 are inversely proportional to alveolar ventilation. When alveolar ventilation increases, both PaCO2 and ETCO2 decrease, and vice versa.
Which zone of the lung (I, II, or III) has the greatest PAO2?

Which zone has the greatest PACO2?
Zone I has the highest PAO2.

Zone III has the highest PACO2
Which zone of the lung has the most negative intrapleural pressure- I, II, or III?
Zone I = Most negative intrapleural pressure.

Zone III = Least negative intrapleural pressure.
Calculate the partial pressure of CO2 in expired gas if ETCO2 = 5% Which law?
ETCO2 = 38 mmHg (0.05 x 760 mmHg).

Law = Dalton's Law of partial pressures.
Which zone of the lung (I, II, or III) shows the greatest increase in blood flow over the distance of the zone?
Zone II shows the greatest increase in BF over the distance of the zone. Zone II = waterfall zone of intermittent blood flow.
How does marked Right-to Left intrapulmonary shunt manifest on radiographs?
marked R-L intrapulmonary shunting is associated with radiographically discernible findings such as pulmonary atelectasis, large pneumothorax, or parenchymal infiltrates.
What is a major consequence of a shunt?

What is a major consequence of dead spacing?
A shunt causes a decreased PaO2.

Mild dead spacing causes increased PaCO2. Severe dead space will cause PaO2 to decrease as well.
What does the PAO2-PaO2 gradient reflect?

What is normal PAO2-PaO2 gradient when breathing room air? When on 100% O2?
The PAO2-PaO2 gradient reflects the degree of R to L shunt. There is normally a small R to L shunt which reflects a normal gradient on room air of 5-15 mmHg. When on 100% O2, the gradient is < 100 mmHg.
What does the PaCO2-PACO2 gradient reflect?

What is normal PaCO2-PACO2 gradient?
The PaCO2-PACO2 gradient reflects dead-spacing.

Normal PaCO2-PACO2 gradient = 2-10 mmHg when breathing room air.
Describe how gravity affects the size of alveoli....
At end-expiration, dependent alveoli are smaller than non-dependent alveoli.
Compared with the apex of the lung, the base of the lung exhibits (when the individual is awake and upright) higher and lower V/Q ratio?
Lower. The V/Q ratio is high in nondependent lung and low in dependent lung.
Estimate PAO2 when % inspired O2 is 50%. 100%.

Estimate PaO2 if the patient is breathing 50%. 100%.
PAO2 can be estimated by multiplying % O2 by 6. (PAO2= % inspired O2 x 6) 50 x 6= 300 mmHg. 100 x 6 = 600 mmHg.

PaO2 can be estimated by multiplying % O2 by 5 (PaO2= % inspired O2 X 5). 50% x 5 = 250 mmHg. 100% x 5 = 500 mmHg
How much O2 is carried by each gram of hemoglobin when saturated?
1.34 ml of O2 is carried by each gram of saturated hemoglobin.
What is the significance of the flat portion of the oxyhemoglobin dissociation curve?

What is the significance of the steep portion of the oxyhemoglobin dissociation curve?
Flat = facilitates the loading of oxygen by the blood because large changes in partial pressure of O2 in arterial blood produce small changes in O2 saturation.

Steep = facilitates unloading of oxygen at tissues because large amounts of oxygen are unloaded from Hgb in response to a small change in the partial pressure of O2.
Define P50. Normal P50 is what?
P50 is the O2 partial pressure at which hgb is 50% saturated.

Normal P50 = 26 - 27 mmHg
What area of the brain is diseased in the Parkinson's patient? Production of what NT is diminished?
Substantia nigra degenerates (found in the brainstem). This leads to a decrease of dopamine.
What causes the symptoms of the patient with multiple sclerosis?

List 4 anesthesia concerns with MS.
Multiple sites of demyelination in the brain and the spinal cord cause the symptoms of MS.

1. Spinal or epidural may exacerbate; 2. Increase Temp may exacerbate; 3. Succs may induce hyperkalemia; 4. Supplement with corticosteroids.
What is Meniere's?

What is the triad of symptoms?

What cranial nerve is involved?
Meniere's disease is a disorder of the membranous labyrinth of the middle ear. Triad is - Vertigo, Tinnitus, hearing loss. CN VIII (acoustic)
What 4 electrolyte disorders lower seizure threshold?
1. Hypocalcemia
2. Hypomagnesia
3. Hyponatremia (TURP syndrome)
4. Hypernatremia
The patient is taking Aminophylline for wheezing. You are considering inducing with ketamine. What is the concern?
The combo of aminophylline and ketamine may cause seizures, especially in the asthmatic patient. The co-administration of these agents decrease seizure threshold.
What opioid is most likely to produce seizures and why?
Meperidine may cause seizures because it is metabolized rapidly to the CNS stimulant/metabilite normeperidine. Normeperidine possesses twice the convulsive properties of meperidine.
What blood vessels supply the loop of Henle?
The vasa recta
Describe renal regulation. Which renal structure appears to mediate autoregulation?
The kidney maintains renal blood flow (RBF) and glomerular filtration rate (GFR) thus preserving solute and water regulation independently of wide fluctuations in BP. Typically operates in arterial pressures ranging from 60-180 mm Hg. Renal vascular resistance appears to be mediated by the variable resistance of the perglomerular AFFERENT arteriole.
State and describe two proposed mechanisma of renal autoregulation
1. myogenic response theory states that increased wall tension in afferent arterioles causes automatic contraction of the smooth muscle fibers in the vessel wall, thereby increasing resistance to flow, and keeping flow constant despite the increase in perfusion pressure.
2. tubuloglomerular feedback mechanism states that increased perfusion pressure will increase filtration, increasing the tubular fluid delivery to the macula densa, which then releases a factor or factors that cause vasoconstriction of the afferent arterioles
Identify the local mediators released in response to hypoxia/ischemia in the kidneys
Stimulates production and release of renal prostaglandins (PGE2, PGD2 and PGI2) and bradykinin
What is the countercurrent system? Identifiy two countercurrent systems in the human body.
An arrangement where inflow runs parallelto and in close proximity to the outflow form some distance. Think of a U-shaped tube. In the human, there are 3 major countercurrent systems: The loop of henle, the vasa recta in the kidney and the blood flow to teh testes through the spermatic arteries and veins.
Compare and contrast teh countercurrent multiplier and the current counter exchanger. Which exist in the kidneys? Testes?
Countercurrent multiplier system (i.e. loop of henle) creates a GRADIENT along the flow pathway. The loop of henle creates an increasing OSMOTIC gradient in the interstitium surrounding the loops, with the maximu osmolality occuring at the tip of the loop. A countercurrent exchange system involves the transfer (exchange) of matter or energy between the inflow and the outflow limbs. In the kidney the vasa recta exchange solutes adn water with the loop of henle, maintaining the osmotic gradient in the interstitium.
List factors that influence the release of ADH
Release is normally regulated by extracellular fluid osmolality. Released with increase in osmolality. Also stimulated by a decrease in plama volume (of 5% or more). Also stimulated by vomiting and drugs such as morphine and nicotine. Alcohol inhibits release of ADH
State two physiological action of ADH
Principal action is to increase the reabsorption of water in the collecting ducts of the kidney. Is also a vasoconstrictor. Constricts peripheral arterioles, thereby leading to an increase in arterial blood pressure
Identify two stimuli, in addition to decreased renal perfusioin pressue, for release of renin.
Hyponatremia and sympathetic nervous system stimulation of beta receptors of the juxtaglomerular cells
What electrolyte promotes release of renin from juxtaglomerular apparatus and controls blood flow through the juxtaglomerular apparatus?
Changes in chloride ion flow past the macula densa stimulate release of renin and also signal the afferent arteriole to dilate, providing more flow to the juxtaglomerular apparatus.
How does glomerular filtration rate (GFR) change if the efferent arteriole dilates relatively more then the afferent arteriole? If the efferent arteriole constrics relatively more than the afferent arteriole?
GFR will decrease if the efferent arteriole dilates more than the afferent. GFR will increase if the efferent arterioles constrict more than the afferent
Do moderate levels of angiotensin II have a greater constrictor affect on afferent or efferent arterioles? What is the significance of this?
When angiotensin II is increased in response to hypotension or volume depletion, efferent arterioles are constricted to a greater extent. This action prevents decreases in GFR
What is BNP? Describe its physiologic role.
BNP is B-type natriuretic peptide, also known as brain natriuretic peptide. BNP is produced in the atria of the heart and functions similarly to ANP-atrial natriuretic peptide. ANP and BNP are released into the circulation (hormone) in response to atrial stretch. Natriuretic peptides bind to G-protein coupled receptors and signal the kidney to excrete sodium and water. Elevated levels in CHF may be a predictor of mortality
How much renal function may be lost before signs and symptoms of renal failure appear?
S and S of renal dysfunction do not appear until 60% of nephron mass is lost. Another way to say this: patients remain asymptomatic when at least 40% of the nephrons continue to function
List and decribe three causes of perioperative acute renal failure.
1. Prerenal (decreased renal blood flow)
2. renal failure (renal tubular damage secondary to decreased renal blood flow, nephrotoxic drugs or release of hemoglobin or myoglobin)
3. postrenal failure (obstruction of urine flow)
List four common electrolyte disturbances associated with chronic renal failure
1. Hyperkalemia
2. Hypocalcemia
3. Hyperphosphatemia
4. Hypermagnesemia
List six physiological consequences of chronic renal failure in addition to electrolyte disturbances
1. anemia
2 pruitus
3. metabolic acidosis
4. coagulapathies
5. suseptibility to infection
6. HTN
Give two reasons for hypocalcemia in the patient with chronic renal failure
2. hyperphosphotemia resulting from decrease in GFR, produces reciprocal decrease in plasma calcium concentration
2. Diminished renal production of Vitamin D3 (vitamin D3, the active form of Vitamin D promotes intestinal absorption of calcium). The kidney convert Vitamin D to its active form
Which muscle relaxants are best used for the patient with chronic renal failure? Why?
Atracurium, vecuronium, cisatricurium, and mivacurium are best because they do not depend on renal excretion for clearance
Administration of either of which two products will treat uremic bleeding if surgery is planned (assuming dialysis is not a feasible option)?
Desmopressin (0.3-0.4 mg/kg IV over 30 minutes) or cryoprecipitate
Endothelial cells release a defective von Willebrand factor in chronic renal failure. What is the implication for this?
Bleeding tendecy increased because normal levels of vWF are required for normal platelet function and hence blood clotting
List four consequences of the coagulopathy seen in the patient with chronic renal failure, and state which occurs most frequently.
1. Gatrointenstinal tract bleeding (most frequent)
2. Epistaxis
3. hemorrhagic pericarditis
4. sudural hematoma
Is each of the following lab values likely to be increased or decreased in chronic renal failure: Creatinine, BUN, hemoglobin, pH, K+, Ca2+?
What are eight pahtophysilogical manifestations of nephrotic syndrome?
1. Proteinuria and hematuria
2. hypertension
3. sodium retention
4. edema
5. hypovolemia
6. hyperlipidemia
7. thromoembolism
8. infectous complications
What laboratory value reflects nephrotic syndrome?
Proteinuria and hypoalbuminemia are HALLMARKS of nephrotic syndrom. thus, serum albumin concentration (normal range 3.5 to 5.0 mg/dl) is expected to be less than 3.5 mg/dl in the patient with nephrotic syndrom
What are five signs of acute glomerulonephritis? What will urinalysis and a blood workup show in this patient?
1. hematuria
2. proteinuria
3. hypertensioin
4. edema
5. increased plasma creatinine
UA will reveal red blood cell casts.
What blood laboratory value is likely to change in acute tubular necrosis?
Serum creatinine concentration increases well above its normal value of about 1mg/dl
What laboratory test is the best measure of end-stage hepatorenal failure?
Urine sodium concentration. U Na <10 mEq/L is indicative of end-stage hepatorenal failure
Why is prevention of myoglobinuria essential? How can the kidneys be protected from myoglobinuria?
Prevention of myoglobinuria is essential to minimize or prevent renal tubular obstruction by pigmented casts. Osmotic diuresis with mannitol may prevent intratubular precipitation of pigments
If you suspect renal dysfunction, how can you estimate the severity?
Creatinine clearance provides an estimate of renal dysfunction. Creatinine clearance of 40-60 ml/min indicates mild renal impairment, 25-40 ml/min indicates moderate renal dysfunction and less than 25ml/min indicates overt renal failure (normal value is 125ml/min)
What test helps distinguish prerenal from renal azotemia?
the fractional excretion of filtered sodium
Define fractional excretion of filtered sodium and explain how this parameter distinguishes prerenal from renal failure.
FE Na = (U/P)Na/(U/P)Cr, where (U/P)Na is the ratio of urine to plama concentration of sodium and U/P Cr is the ratio of urine to plasma concentration of creatinine. Fe Na is less that 0.01 (<1%) for prerenal failure and FE Na is greater then 0.01 (>1%) for renal failure
State the specificity and sensitivity of the fraction excretion of sodium in distinguishing between prerenal azotemia and acute tubular necrosis (renal azotemia)
the sensitivity and specificity of fractiton excretion of sodium of <1% in differentiating prerenal azotemial from acute tubular necrosis are 96% and 95% respectively
What is the haldane effect?
High po2 promotes co2 unloading in the lungs
low po2 helps co2 loading in the tissues
What are conditions that can > anesthetic uptake?
Anesthetic over pressurization
> the Fi of inspired gas
< co
Pacemaker programing codes... what are the first 3 in order
goal for mitral stenosis
for all stenotic lesions
Slow and sinus
maintain preload
avoid < SVR; maintain high svr
what are drugs that prolong NDMR's?
Mag; < Ach release
Ca channel blockers
ABX: Mycins; clinda....ect........
where is pseudocholinesterase produced and where is it found
Made in the liver
found in the plasma
2 drugs that are metabloized by pseudocholinesterase
what is the substrate for pseudocholinesterase ?
dibucaine number is a function of.....
% of inhibition by dibucaine
What drugs are unsafe in AIP?
Damage to what nerve causes an inability to aBduct the thumb?

A. Radial
B. Median
C. Ulnar
B. Median
What nerve leaves the fascial sheath early in the axilla and lies within the coracobrachialis muscle?
A. Ulnar
B. Radial
C. Median
D. Musculocutaneous
D. Musculocutaneous
What approach to the brachial plexus is associated with the greatest risk of pneumothorax?
A. Interscalene
B. Supraclavicular
C. Infraclavicular
D. Axillary
B. Supraclavicular
What is the terminal branch of the femoral nerve?
A. Tibial
B. Saphaneous
C. Sural
D. Superficial peroneal
B. Saphaneous
Geriatric cardiovascular changes that occur include all except:

a. Elevated afterload
b. Left ventricular hypertrophy
c. Elevated systolic blood pressure
d. Increased arterial elasticity
d. Increased arterial elasticity
Which of the following physiologic changes occurs in the geriatric patient?

a. Decreased lung compliance
b. Decreased chest wall compliance
c. Decreased residual volume
d. Decreased closing capacity
b. Decreased chest wall compliance
Aged men have a prolonged effect with Anectine but aged women do not. what explains this?

a. Lipid solubility.
b. Water solubility.
c. Lower plasma cholinesterase concentration
d. Fewer motor end-plates
c. Lower plasma cholinesterase concentration
As part of the normal aging process, what is responsible for a decline in heart rate?

A. Increased vagal tone
B. Decreased barorerecptor function
C. Decreased sensitivity to adrenergic receptors
D. All of the above
E. A & C
A & C
The normal aging process is responsible for which of the
following respiratory effects?

a. ↑ chest wall compliance & ↑ pulmonary elasticity
b. ↑ chest wall compliance & ↓ pulmonary elasticity
c. ↓ chest wall compliance & ↑ pulmon
d. ↓ chest wall compliance & ↓ pulmonary elasticity
All of the following neuroendocrine effects are associated with aging EXCEPT:

A. ↓ heat production
B. ↑ heat loss
C. Hypothalmic temperature regulating centers reset at a higher level
d. ↑ insulin resistance
C. Hypothalmic temperature regulating centers reset at a higher level
Administration of a given volume of epidural anesthetic
in geriatric patients tend to result in

A. ↑ cephalad spread & ↑ duration of action
B. ↑ cephalad spread & ↓ duration of action
C. ↓ cephalad spread & ↑ duration of action
B. ↑ cephalad spread & ↓ duration of action
In geriatric patients, recovery from anesthesia with a
volatile anesthetic can be prolonged due to

A. ↑ volume of distribution
B. ↓ hepatic function
C. ↓ pulmonary gas exchange
D. All the above
D. All the above
2. When making a lateral approach the needle will not pass through these 2 structures
A. Ligamentum flavum, Supraspinous ligament
B. Interspinous ligament, Ligamentum flavum
C. Supraspinous ligament, Interspinous ligament
C. Supraspinous ligament, Interspinous ligament
Absolute contraindications for spinal anesthesia are:
A. Patient Refusal
B. Infections at puncture site
C. Severe coagulation abnormalities
D. Raised ICP
E. All of the Above
E. All of the Above
Who regulates gas purity?

Who enforces the purity standards?

How often should cylinders be inspected?
Regulates gas purity = USP/NF or the US pharmacopea / National formulary.

FDA enforces purity standards.

Cylinders should be inspected at least every 5 years
For which gases can the amount remaining in the cylinder be determined by the pressure gauge?
Oxygen, Air, Helium, and nitrogen. These gases are not in liquid form like N20 and CO2.
What pressure indicates that there is no liquid left in the N20 tank? How full is the tank at this time? How many liters are left?
N20 pressure below 745 psi indicates that the cylindr is less than 1/4 (25%) full and there is no liquid remaining. 1/4 fulls = about 400 L of N20 left.
Identify 4 components of the machine that are exposed to high pressures.

Identify 4 components exposed to low pressures.
High pressures = hanger yoke, Yoke block with check valves, cylinder pressure gauge, cylinder pressure regulators.

Low pressures = distal to flow meters = Thorpe tubes, vaporizers, check valves, common gas outlet.
When the bourdon gauge reads zero, what is the pressure in the tank?
1 atmosphere
What is the primary disadvantage of the auxillary oxygen flowmeter on the machine?
The auxillary oxygen flowmeter is used for supplemental O2. If pipeline supply has lost pressure, the auxillary O2 flowmeter becomes unavailable.
Calibration of flowmeters is based upon what physical property of gases: density, or viscosity?
Flowmeters are calibrated for specific gases based upon the viscosity at low flows and density at high flows.
What is the Bohr effect?

What is the Haldane effect?
Bohr = The shift of the oxyhemoglobin dissociation curve caused by carbon dioxide entering or leaving the blood is the bohr effect.

Haldane = describes how changes in PO2 in the blood alter the amount of CO2 carried by the blood.
What determines mixed venous O2? (MVO2)?
MVO2 is determined by:
1. O2 delivery to tissues (CO, HGB concentration)

2. Oxygen consumption (MH, shivering, thyroid storm)

MVO2 is the BEST measurement for determining the adequacy of CO.
In which direction do inhalational agents or IV agents shift the OxyHGB dissociation curve? Why?
administration of inhalational or IV agents may cause the OxyHGB Dissociation curve to shift to the RIGHT becasue respiratory depression permits PaCO2 to increase.
What is total quantity of O2 delivered to, and used by, the tissues each minute? (in ml/min and ml/kg/min)

How much CO2 is normally produced and eliminated per minute? Per ml/kg/min?
O2 = 250 ml/min (3-4 ml/kg/min)

CO2 = 200 ml/min (2.4 - 3.2 ml/kg/min)
Iron is in what state in methemoglobinemia?

What is the significance?
Normal Hgb has iron in the ferrous state (Fe2+). Oxygen carriage by normal Hgb is excellent. Met-Hgb has iron in the ferric state (Fe3+). Oxygen carriage is poor.
What is the carbon dioxide content of room air in:

Vol %?
Partial Pressure?
Carbon dioxide content of room air = 0.03%

partial pressure of CO2 in room air = 0.23 mmHg.
Compare th solubilities of O2 and CO2 in blood.
CO2 is about 20 times more soluable. The coefficient for CO2 = 0.067 and for O2 = 0.003.
Units are ml O2/100 ml blood/mmHg.
What are 4 ways CO2 is transported in the blood? What percentage does each exist?
CO2 is carried:
1. Bicarbonate Acid - HCO3- (90%)
2. Protein Bound (5%)
3. Physically dissolved in solution (5%)
4. Carbonic Acid - H2CO3- (<1%)
What is the role of carbonic anhydrase in the RBC?
Carbonic Anhydrase is an enzyme in the RBC that accelerates the conversion of H2O and CO2 to the carbonic acid (H2CO3) and then to bicarbonate ions. Carbonic Anhydrase is responsible for converting CO2 to bicarbonate ions.
After being formed, bicarbonate moves out of the RBC into plasma in exchange for what? What is this called?
Bicarbonate diffuses out of RBC in exchange for chloride ions. This is the chloride shift. It is also known as the Hamburger shift.
Where are the primary repsiratory centers (dorsal and ventral) located?

Where are the secondary respiratory centers (Apneustic and pneumotaxic centers) located?
The primary repsiratory centers (dorsal and ventral) are located in the medulla of the brainstem.

The secondary respiratory centers (Apneustic and pneumotaxic centers) are located in the Pons of the brainstem.
Identify the anatomic site where opioids produce respiratory depression? What opioid recepter causes respiratory depression?
All opioids cause dose-dependent depression of respirations through direct mu-2 stimulation at the brainstem respiratory centers located superficially in the floor of the 4th ventricle (i.e. medulla and pons)
What is the single most important factor responsible for directly stimulating central chemoreceptors? How are these same ions generated in CSF?
H+ ions in the CSF directly stimulate central chemoreceptors. CO2 that diffuses into CSF is converted by carbonic anhydrase first to carbonic acid (H2CO3) and then to H+ and Bicarbonate (HCO3-)
What 3 physiologic parameters do peripheral (carotid and aortic) chemoreceptors respond? What stimulates peripheral chemoreceptors the most?
Name 3 exogenous substances that stimulate peripheral chemoreceptors.
Peripheral (carotid and aortic) chemoreceptors respond to PaO2, PaCO2, and pH. They are MOST sensitive to PaO2- but not until PaO2 < 50 mmHg.

Cyanide, Doxapram, and Nicotine are 3 exogenous substances that also stimulate.
How much of the ventilatory response to an increase in PaCO2 is mediated by the central chemoreceptors? Peripheral chemorceptors?
The ventilatory response to an increase in PaCO2 is mediated PRIMARILY by the central chemoreceptors. The effect of CO2 is 7 times more powerful on central chemoreceptors than on peripheral chemoreceptors.
What are pulmonary J-receptors? Which nerve fibers types innervates pulmonary J receptors?
Juxtapulmonary-capillary receptors are located in the walls of the pulmonary capillaries and appear to be stimulated by pulm vascular congestion leading to tachypnea. C-fibers innervate J receptors.
What are the benefits of smoking cessation 2-3 months prior to anesthesia? How long after quitting do these benefits occur?
The benefits of smoking cessation include: 1. Improved ciliary function, 2. improved closing volume, 3. increases MMEF, 4. Decreased sputum. These benefits occur within 2-3 months of smoking cessation.
What are the benefits of smoking cessation 12-24 hours preoperatively?
Smoking cessation 12-24 hrs preoperatively reduces carboxyHGB and nicotine levels. P50 increases from 23 to 26 mmHg. CarboxyHGB levels decrease from 6.5% to 1.1%. Short term cessation does NOT decrease post-op morbidity and mortality.
Which cell type can cause bronchoconstriction? How?
Mast cells can degranulate and release histamine; which can cause bronchoconstriction.
How do osmotic and hydrostatic pressures compare in the alveolar capillaries? What keeps edema from forming in the normal lung?
Colloid osmotic pressure of 28 mmHg (force holding H20 in capillaries) greatly exceeds hydrostatic pressure of 6-8 mmHg (force driving H20 out of capillaries). High colloid osmotic pressure provides a safety factor for preventing pulmonary edema.
What are the 2 most common reasons for pulmonary edema? What is the most common cause of acute pulm edema?
Pulm edema results from: 1. increase in pulm hydrostatic pressure (LV failure) or 2. an increase in permeability of alveolar capillary membranes. The most common cause of acute pulm edema is increased hydrostati pressure secondary to LV failure.
What is the major pathophysiologic manifestation of ARDS? Why does this occur?

In ARDS, what happens to pulmonary compliance? WOB? Pulm edema?
Hypoxemia is the major manifestation of ARDS. Hypoxemia develops secondary to atelectasis and a R to L intrapulmonary shunt.

Compliance = decreased, WOB = increased, Pulm edema = increased
What is the most common cause of histotoxic hypoxia?
The most common case of histotoxic hypoxia = cyanide poisoning.
What is the earliest and most reliable sign of aspiration?

The most serious complication of aspiration is what?
Hypoxemia is the earliest and most reliable sign of aspiration.

The most serious complication of aspiration is ARDS. (AKA aspiration pneoumonitis / Mendelson's syndrome).
What 2 factors increase the risks associated with aspiration pneumonitis?
When intragastric volume is greater than 25 ml and intragastric pH is les than 2.5.
The affinity of carbon monoxide for Hgb is how many times greater than the affinity of oxygen?
The affinity of carbon monoxide for Hgb is 200 - 250 times greater than that of oxygen.
Why is administration of oxygen the treatment for carbon monoxide poisoning?
The elimination half-time of carboxyHGB is 250 minutes. 100% O2 increases the dissociation of carbon monoxide from HGB and decreases the elimination half-time to about 50 minutes.
With a pneumothorax, administration of 50% N20 will result in how much of an increase in size of the pneumothorax?
The pneumothorax will double with administration of 50% N20.
What is sarcoidosis? Sarcoidosis mostly effects what tissues? How does sarcoidosis affect the airway?
Sarcoidosis is a systemic granulomatous disorder that can involve many tissues. It has marked predilection for the thoracic lymph nodes and lungs. Restrictive lung disease is associated with the lung involvement. Sarcoidosis can cause airway obstruction due to the presence of hyperplastic lymphoid tisue.
What is the major anesthetic concern with cystic fibrosis? Why? What drugs should be avoided?
The concern is thick mucus secretions. Retained secretions cause pulmonary infections and airway obstruction. CF patients develop COPD with reduced VC, lower PaO2, high PaCO2, and reduced FEV-1. Avoid robinol and atropine due to thickening of secretions.
What is the universal ABG finding during an asthma attack? Would you expect CO2 retention?
Hypoxemia is a universal ABG finding during an asthma attack. Frank ventilatory failure with CO2 retention (hypercarbia) is uncommon. Hypocarbia and respiratory alkalosis are also common during an asthma attack. . CO2 retention is a LATE finding indicating severe airway obstruction.
What 2 types of drugs should be avoided in a patient with asthma?
Beta-2 blockers (propanolol/labetolol)

Histamine releasing drugs (morphine, succs, mivacurium, atracurium)
What anatomical changes of the thoracic cage would you expect in a COPD patient?
Barrel chest - refers to increased A-P diameter which may be equal or exceed lateral diametrer. Sternum becomes prominent. Kyphosis of the thoracic spine. Little motion to the thoracic cage even after forced breathing.
What happens to airway resistance in a patient with COPD? What happens with pulmonary compliance?
In COPD, airway resistance increases because of bronchiole obstruction and pulmonary compliance increases.
What is the underlying pathphysiology of chronic bronchitis? What Pa02 should the patient be kept under?
Blue bloaters = chronic bronchitis. Blood oxygenation is not maintained. Cor pulmonale with resultant peripheral edema, heart failure, and pulnonary HTN develop. PaO2 should be kept under 60 mmHg- higher than 60 mmHg may result in resp failure.
Describe the pathophysiology underlying emphysema.
Pink puffers = emphysema = destruction of lung tissue that results in loss of elastic recoil of the lungs. When dyspneic, these people often purse their lips to delay closure of small airways. Compliance of the lungs increase and elastic recoil decreases.
What 3 pre-op tests would you order for a patient with scoliosis / kyphoscoliosis?
1. PFT
2. ABG
3. EKG
What 2 signs are diagnostic of chronic bronchitis?
1. Chronic cough
2. Sputum production on most days for 3 months a year for at least 2 years.
Is tracheal stenosis an example of obstructive or restrictive disease? Is it an example of an intrathoracic or extrathoracic obstruction?
Tracheal stenosis is an example of obstructive disease. Becomes symptomatic when the lumen of the trachea in an adult becomes less than 5 mm in diameter. It's also an example of fixed extrathoracic obstuction.
Is scoliosis obstructive or restrictive disease? Would you expect FEV1/FVC to be low, normal, or high?
Scoliosis affects the vertebral column and thus the thoracic cage and is therefore restrictive. FEV1/FVC may be normal or slightly elevated, even though each value is reduced / restricted.
List 4 common causes of metabolic acidosis?
1. Ketoacidosis
2. Lactic acidosis
3. Renal failure
4. Toxic dose of salicylates
List 3 common causes of metabolic alkalosis.
1. Vomiting
2. NG suction
3. Hypokalemia as a result of diuretics
Normal ranges for:
pH = 7.35 - 7.45
PCO2 = 35 - 45 mmHg
HCO3 = 22 - 27 mEq/L
What is normal HCO3- / H2CO3 ratio?

What is the significance?
Normal HCO3-/H2CO3 ratio is 20:1

the pH increases when the ratio increases, and pH falls when the ratio decreases.
SE of cholinesterase inhibitors include each of the following EXCEPT:
a. bradycardia
b. increased salivation
c. bronchoconstriction
d. mydriasis
You would avoid which agent if the patient with glaucoma is being treated with echothiophate?
a. Remifentanil
b. Thiopental
c. Mivacurium
d. Edrophonium
Which of the following agents LEAST depresses the activity of plasma cholinesterase?
a. Edrophonium
b. Neostigmine
c. Pyridostigmine
d. Echothiophate
A farmer who one hour ago was spraying his crops with organophosphate insecticide complains of abdominal cramps, muscle weakness, and blurred vision. He is wheezing and bradycardia. Treatment of this condition might reasonably include each of the followin
a. physostigmine
Which of the following 12 lead ECG changes would be seen with inferior subendocardial injury?
A. ST depression in lead II
B. ST elevation in lead II
C. ST depression in lead V1
D.ST elevation in lead I
(A). Injury to myocardial cell results when the ischemic process is more severe. Subendocardial injury on ECG is manifested by ST depression, and subepicardial or transmural injury is manifested as ST elevation.
The leads that represent the inferior aspect of the heart are leads II, III, aVF. Anterior aspect of the heart include V1-V4 and lateral aspect of the heart include I, aVL, V1-V2.
This gas law describes that the diffusion of gases through tissues such that the rate of transfer of a gas through a sheet of tissue is dependent on tissue area, tissue thickness, concentration gradient, solubility of the molecules, molecular size and wei
Henry's Law
Which law explains the expansion of an LMA cuff during autoclave sterilization?
Which law explains the concentration effect, second gas effect, and diffusion hypoxia?
Which nerve innervates the foot and is NOT a branch of the sciatic?
a. Deep peroneal
b. Saphenous
c. Posterior tibial
d. Sural
b. Saphenous
The saphenous nerve is a terminal branch of the femoral nerve and the only innervation of the foot that is not part of the sciatic system.
When a hydrophilic opioid is used for intrathecal or epidural anesthesia,
a. onset is slow and duration is short
b. onset is slow and duration is prolonged
c. onset is fast and duration is short
d. onset is fast and duration is prolonged
B. Poorly lipid soluble opioids (Morphine) crosses lipid membranes slowly thus result in slower onset of analgesia but longer duration of action than lipid soluble opioids (e.g. Fentanyl, Sufentanil ) that readily diffuse through lipid membrane following neuraxial placement.
What substance decreases the release of Substance P in the spinal cord?
a. Enkephalin
b. Acetylcholine
c. Norepinephrine
d. Serotonin
A Endogenous opiate system via enkephalin act presynaptically to hyperpolarize primary afferent neurons and inhibit release of Substance P reducing the number of pain impulses ascending the spinothalamic tract. Ach and NE are neurotransmitters found in ANS at pre and post synaptic junction, has no effect with pain impulse. Serotonin found in CNS has various functions include regulation of mood, appetite, sleep and cognitive function such as memory & learning.
Mu-2 receptors cause:
a. dysphoria
b. respiratory depression
c. pruritus
d. miosis
B. Mu-2 receptors primarily responsible for spinal analgesia with following effects:
respiratory depression, marked constipation and physical dependence .
Reference: Stoelting & Miller, Basics of Anesthesia, 5th ed, 2007, p. 114
Which drugs are NOT known to potentiate succinylcholine?

a. phenelzine, cyclophosphamide, metoclopramide
b. esmolol, pancuronium, oral contraceptive
c. primidone, dantrolene, ketamine
d. All of the Above (potentiate succinylcholine)
c. primidone, dantrolene, ketamine
Plasma K+ concentration has a(n) ________ relationship with pH, and changes _______ mEq/L per 0.1 unit change in pH.
Inverse, 0.6.
Dosing of neuromuscular blocking agents in the patient with hypermagnesemia should be adjusted according to which of the following?
Dosage should be decreased 25-50%. Increased serum levels of Mg++ decrease acetylcholine release (AcH) and reduce sensitivity of the motor end-plate to AcH. Dosages of NMBAs should be decreased by 25-50%.
All of the following causes of metabolic acidosis would be expected to produce an increased ion gap EXCEPT:
a. Salicylate toxicity.
b. Diarrhea.
c. Renal failure.
d. Rhabdomyolysis.
b. Diarrhea. Metabolic acidosis with an increased anion gap indicates the accumulation of nonvolatile acids, such as in ketoacidosis or lactic acidosis. A normal (hyperchloremic) anion gap in the setting of metabolic acidosis occurs as Cl- ions increase to replace lost HCO₃ ions, as in GI losses of HCO₃ (diarrhea, ileostomy, pancreatic fistula).
6. From the following electrolyte values, calculate the anion gap. Is it increased, decreased, or normal?
Na+ = 135; Cl- = 104; HCO₃ = 17.
The equation for anion gap is anion gap = [Na+] – ([Cl-] + [HCO₃-]). The normal range for anion gap is 7-14 mEq/L. Using the above equation, anion gap = 135 – (104 + 17) = 14 mEq/L. The value is within normal range.
Where do local anesthetics work after injection into the intrathecal space?
LA work on:

Spinal nerve roots
Spinal nerve rootlets
Spinal Cord
What is the result of blocking:
B fibers?
C fibers?
A-delta fibers?
A-gamma fibers?
A-beta fibers?
A-alpha fibers?
B = venodilation and hypotension
C and A-delta = loss of pain and temp
A-gamma = loss of muscle tone
A-beta & A-alpha= loss of motor function and proprioception
What nerve fibers are responsible for loss of proprioception?
A-alpha and A-beta
what is the order of nerve fiber blockade during a spinal?
B fibers
C fibers and A-delta
(B = first.....A-alpha = last)
What nerves fibers are least likely to be blocked during a spinal?
A-Alpha are the most difficult to block
What sensations are lost first after injection of a spinal?
Pain and temperature are lost first; which are carried by C and A-delta fibers?
The sympathetic response to spinal anesthesia occurs because LA act on what neurons?
The sympathetic outflow is inhibited during spinal anesthesia because LA are blocking conduction in the sympathetic preganglionic efferents.
A spinal is administered and the patient reports tingling in the little finger of the right and left hand. What is the level of the block?
Sensory block is at C8 if the little finger and ring finger have abnormal sensation. Sensory block at C6 results in paresthesia of the thumb and index finger. Sensory block at C7 results in paresthesia of the middle fingers.
What level of spinal block would be appropriate for a patient with kidney pain?
The kidneys receive sensory innervation from spinal levels T10 - L2. Therefore, a block to T10-L2 is usually sufficient for kidney pain relief and referred pain to the kidneys.
Spinal anesthesia to what dermatone level would be required for lower abdominal surgery?

For upper abdominal surgery?
Lower abdominal = T6

Upper abdominal = T4
Blockade to which spinal segments will take away urinary bladder tone and inhibit the reflex to void?
Blockade of lower lumbar and sacral spinal segments )S2-S4) will take away urinary bladder tone and inhibit the reflex to void.
Compared to the level of sensory block associated with spinal anesthesia, motor blockade and sympathetic blockade occurs where?
Motor blockade occurs 2-3 segments lower than sensory block.

Sympathetic block occurs 2-6 segments higher than sensory block.
How is the baricity of a LA determined?
The measure of baricity is specific gravity. Specific gravity is the density of the LA solution divided by the density of CSF at 37 degrees.
The anesthetic level reached after subarachnoid block is determined by what 4 factors?
1. Baricity of the solution
2. Concentration
3. Countour of spinal canal
4. Position of the patient
State the maximum dose (mg) of agent for spinal anesthesia with:
Lido = 60 mg
Bupivicaine = 9 - 15 mg
Ropivicaine = 15 - 22.5 mg
Tetracaine = 10 mg (hypobaric), 12 mg (hyperbaric), 15 mg (isobaric)
Of the LA administered intrathecally, which produces the most profound motor block?
What is the duration of lidocaine when used for spinal anesthesia with and without epinephrine?
For spinals, the duration of sensory block by lidocaine is 45 - 60 minutes without epinephrine and 60 - 90 minutes with epinephrine.
How long does it take for subarachnoid block to reach its most cephalad level?
Subarachnoid block usually reaches its highest level 20 minutes after spinal injection, although the level may move cephalad for 30 minutes.
What are 7 absolute contraindications of spinal anesthesia?
1. Patient refusal
2. Infection at site
3. High ICP
4. Clotting disorder
5. Brain tumor
6. Spinal Cord disease
7. Severe hypotension
Others not stated in valley: provider inexperience, severe aortic stenosis, Shock
How long does it take the half-life of a LA administered intrathecally compare with the half-life when administered epidurally?
The half-life of a LA is longer when injected intrathecally compared with epidurally.
What is the hydrostatic pressure in the epidural space?

What is the significance of this?
The hydrostatic pressure in the epidural space is negative (subatmospheric), which means that a drop of fluid placed in the hub of the needle with the tip in the epidural space will get sucked in.
Where do local anesthetics work after epidural administration?
LA is found in the nerve roots, nerve rootlets bathed by CSF, and within the spinal cord.
With epidural blockade, what is the most sensitive indicator of initial sensory block?
Assessment of the sensation of temperature is the most sensitive indicator of sensory block.
Compared with the level of sensory block associated with epidural anesthesia, sympathetic and motor blockade occur where?
With epidural blockade, sympathetic block occurs at the same level as sensory block and motor block may be 4 dermatones lower than sensory block.
Which of the following LA produces the greatest motor block when administered epidurally?
Lidocaine 1%
Bupivicaine 0.25%
Chloroprocaine 3%
Mepivicaine 1%
Epidural chloroprocaine 3% produces the most profound motor block.
What combo of LA and opioids is effective when administered epidurally for post-op pain control and permits ambulation?
Bupivicaine (0.0625 - 0.125%) in combo with Morphine (0.1 mg/ml) or fentanyl (5 mcg/ml) provides excellent analgesia without motor blockade.
State 2 reasons for giving a test dose after an epidural?

How long should you wait after giving a test dose?

How long does it take a test dose with EPI to reach the heart inadvertent IV injection.
2 reasons for a test dose is to determine that the catheter is not intravascular and not intrathecal.
What structures are passed though when performing an epidural with the paramedian approach?
Skin, SubQ tissue, paraspinous muscle mass, and ligamentum flavum.
How far is the epidural space from the skin in the obese adult, non-obese adult, and thin patients?
the epidural space is 4 cm from the skin in 50% of adults and 4-6 cm in 80% of the population. In obese patients it may be over 8 cm and in thin patients in may be less than 3 cm.
How far should the catheter be threaded into the epidural space?
The catheter should be threaded 3-5 cm into the epidural space.
Negative pressure during a caudal anesthetic placement is detectable after going through what structure?
The sacrococcygeal ligament. This ligament is an extension of the ligamentum flavum.
What are the 2 most commonly used agents, doses, and volumes appropriate for caudal anesthesia?
Bupivicaine (0.125% - 0.25%) and Lidocaine (1%) are the most commonly used agents. The volume of LA ranges from 0.5 ml/kg for a sacral block to 1.25 ml/kg for a mid thoracic block.
What volume of LA is injected for a 70 kg adult male of average height for a caudal block?
1-2 ml of LA per spinal segment. At least 12 - 15 ml is required to adequately fill the sacral canal.
The needle is inserted at what angle for lumbar epidural anesthesia? And for thoracic epidural anesthesia?
For lumbar anesthesia, the needle is introduced at a right angle (90 degrees). For thoracic epidural anesthesia, the needle is inserted upward at an angle that is 40 degrees to the ligamentum flavum.
What 2 nerves are derived from the posterior cord of the brachial plexus?
Axillary and radial nerves.
What 2 nerves are derived from the lateral cord of the brachial plexus?
Musculocutaneous and median nerves.
What 2 nerves are derived from the medial cord of the brachial plexus?
Median and ulnar nerves.
Describe the landmarks and relative needle location in order to perform a median nerve block at the wrist? How much LA is required?
A 22 gauge needle is directed just medial to the ulnar artery pulse. If the ulnar pulse is not palpable, the needle is placed just medial to the flexor carpi radialis. A total volume of 3-5 ml of LA is injected to block the median nerve.
1. Damage to what nerve causes an inability to adduct the thumb?

2. Damage to what nerve causes inability to abduct the thumb?
1. The median nerve.

2. The radial nerve
What 4 functional changes occur after the radial nerve is blocked by LA?
When the radial nerve is blocked, there is:
1. Inability to supinate the forearm.
2. inability to extend the wrist.
3. Inability to extend the abduct the thumb.
4. Inability to extend the metacarpophalangeal joints.
What muscle of the thumb is innervated soley by the ulnar nerve?
Adductor pollicis
Describe the anatomic relationships of the median, ulnar, and radial nerves to the axillary artery.
The median nerve lies anterior (superior). The ulnar nerve is medial and slightly posterior (inferior). The radial nerve is posterior and slightly lateral. Mnemonic: RUMM - PISS)
What nerve is least likely to be blocked with the axillary approach to the brachial plexus? Why?
The musculocutaneous nerve is least likely to be blocked becuase in the axilla, this nerve has already left the sheath and lies in the coracobrachialis muscle.
What nerve innervates the medial aspect of the upper arm?
The medial cutaneous nerve of the arm and the intercostobrachial nerve innervate the upper arm to the elbow.
What syndrome is associated with stellate ganglion blockade? What are six signs of this syndrome?
Horner's syndrome occurs when the stellate ganglion is blocked. On the same side of the head/face as the side on which the stellate ganglion is blocked- ptosis, miosis, facial flushing, increased temperature, anhydrosis, and nasal congestion.
What nerve is often not blocked in an interscalene approach to a brachial plexus block?
The lower (inferior) trunk (C8 - T1) of the brachial plexus may be inadequately blocked. Since the ulnar arises from the inferior trunk, supplemental ulnar block may be required.
Your patient requires hand surgery: which upper extremity block would not be appropriate?
The interscalene approach to a brachial plexus because this targets trunks.
What is the major advantage of the supraclavicular approach to the brachial plexus?
Because the brachial plexus is blocked where it is most compactly arranged (at the level of the three trunks), there is minimal possibility of missing peripheral or proximal nerve branches because the failure of LA to spread.
What are the indication for the axillary block?
Surgical procedures from the mid humerus to the hand.
What periperal nerve blocks are appropriate for shoulder surgery?
Interscalene or suprascalene. Axillary block is inadequate for shoulder surgery.
What is thoracic outlet syndrome? What are the implications of this syndrome with regard to patient positioning?
Thoracic outlet syndrome results from compression of the brachial plexus and subclavian artery at the thoracic outlet between the first rib and the clavicle or between the anterior and medial scalene muscles. Patients complain of weakness, numbness, or parasthesias in the affected upper extremity after the arms are overhead.
What is the 3-in-one block?
It is another name for the lumbar plexus block. It involves the femoral, obturator, and lateral femoral cutaneous nerves.
What nerve can be blocked in a popiteal fossa block?
The sciatic nerve can be localized in the upper area of the popiteal fossa. The goal is to block the sciatic nerve before it branches into the tibial and peroneal nerve.
The nerves of the foot are branches of what 2 major nerves?
The nerves of the foot are ultimately derived from the femoral and sciatic nerves.
Of the 5 sensory nerves to the ankle, which 3 lie most superficial?
All the S's.....sural, superficial peroneal, saphenous nerves.
Name the 1 sensory nerve that does not arise from the sciatic nerve?
The saphenous nerve is the terminal branch of the femoral nerve.
What are the functions of each of the five nerves of the ankle and foot?
Saphoneous - supplies sensation to the anteromedial foot. Deep peroneal nerve permits toe extension and sensation to the medial half and dorsum of the foot. Superficial peroneal - sensation to the dorsum of the foot and all 5 toes. Tibial - sensation to the heel, medial sole and lateral sole of the foot. Sural - senastion of the lateral foot.
What nerve causes flexion of the foot? What nerve causes extension of the foot?
Flexion - medial plantar and lateral plantar (branches of the tibial nerve.

Extension - Peroneal nerve.
Rank LA injection sites from fastest absorption to slowest.

Blood, intercostal, intratracheal, caudal, cervical, epidural, sciatic, subcutaneous, subarachnoid.......CHECK ANSWER!
Concentration achieved after a LA administered transtraceally most closely resembles what site?
Sublingual - At both intratracheal and sublingual injection sites, LA are absorbed across mucus membranes.
What 2 LA should be avoided when doing a Bier Block? Why?
Chloroprocaine is avoided because it is associated with thrombophlebitis.

Bupivicaine is avoided due to possible cardiotoxicity.
List 8 contraindications to Bier Block?
1. Patient refusal
2. Mod-severe HTN disease
3. Athletic build
4. Skeletal muscle disorder
5. Allergy
6. Untreated heart block
7. Sickle Cell
8. Infection/Cellulitis
Which nerve are blocked in the cervical plexus block?
The ventral rami of C1-C4 form the cervical plexus. However, the first nerve (C1) ia a motor nerve with no sensory distribution. therefore the cervical block anesthetizes C2 - C4
List 2 indications for a facial nerve (CN VII) block?
1. To releive spastic contractions of facial muscles.

2. To treat herpes zoster involvement of the facial nerve.
What are 4 determinants of systemic absorption of a LA?
1. Total dose administered
2. Vascularity of the site
3. Presence of a vasoconstrictor
4. Properties of the drug (protein binding, lipid solubility, absorption)
List 10 symptoms of LA toxicity in order of appearance?
1. circumoral numbness
2. Tinnitus
3. Muscle twitching
4. hypotension
5. myocardial depression
6. siezures, 7. unconsiousness, 8. resp arrest, 9. coma, 10, CV depression
After epidural injection of LA, the patient complains of lip numbness. O2 is given. What other prophylactic measures should be taken?
Suspect LA toxicity. After O2, hyperventilate the patient to produce hypocapnia and constriction of cerebral vessels to reduce the amount to LA going to the brain. Hypocapnia raises the seizure threshold.
List 6 complications of spinal anesthesia. What is the most common and 2nd most common?
1. PDPH (2nd most common)
2. Backache (most common)
3. High spinal
4. Nausea
5. Urinary retention
6. Neurologic injury (rare)
The likelihood of PDPH is increased by what 5 factors?
1. Younger > older
2. Females > Males
3. Larger needles > smaller
4. Pregnant > non-pregnant
5. History of multiple punctures
What is the occurance rate of headaches after an unitentional dural puncture with an 18 gauge epidural needle in the pregnant patient?
As high as 70 - 80% will get a PDPH.
What is the cause of respiratory arrest after administration of spinal anesthesia?
Apnea occurs with a high spinal due to ischemia of the brainstem medullary respiratory centers secondary to profound hypotension.
Complications of epidural block differ from subarachnoid block in what way?
There is an increased likelihood of IV injection and systemic toxicity with an epidural block compared with a spinal block.
What is the most common reason for a backache after an epidural or a spinal?
The relaxation of the paraspinous muscles allowing for stretch of the joint capsules and spinous ligaments.
List 3 common complications associated with the interscalene approach to the brachial plexus?
1. Horners syndrome
2. RLN injury
3. Phrenic nerve injury
What is the most common complication of the interscalene block?
Phrenic nerve block (some books say up to 100% of interscalene blocks affect the phrenic nerve). 23 - 100%
Describe the onset and patient's description of tourniquet pain. Which nerve fibers mediate tourniquet pain?
about 45 minutes after a tourniquet is inflated, the patient may complain of dull, aching pain, or become restless; even with adequate analgesia for the surgery. The pain is cause by transmission of C and A -delta fibers.
The incidence of needle-induced nerve injury is greatest with which of the following regional techniques: spinal, epidural, axillary, beir block?
Axillary block has the highest incidence of nerve injury (0.8 - 2.8%). Spinals and epidurals cause nerve injury in 0.01% of patients.
What are 3 signs and symptoms of cauda equina syndrome?
1. Urinary and fecal incontinence
2. Paralysis of the lower extremity
3. Diminished sensations of the perineum.
What type of muscle is found in the pyloric sphincter?
The pyloric sphincter is a short, relatively poor barrier of smooth muscle between the stomach and the duodenum.
What type of muscle is found in the GI tract? Identify the arrangement of this muscle.
The tunica muscularis of the GI tract is comprised of 2 layers of smooth muscle: the inner layer is circular, the outer layer is longitudinal.
What is the gastric pH range in a fasted patient?
pH in the fasted patient = 1.6 - 2.2
Identify 7 situations/conditions that delay gastric emptying.
1. Obesity
2. Pregnancy
3. Opioids
4. Diabetes
5. Trauma
6. Pain
7. Anxiety
Describe the pathophysiology of cholecystokinin (CCK).
Cholecystokinin (CCK) is a 33 amino acid peptide and is produced by cells in the mucosa of the small intestine. It is released in response to the presence of fats in the intestinal contents. It stimulates gall bladde contraction and the release of pancreatic enzymes, while inhibiting gastric motility. CCK provide time and conditions to digest fats.
Is bile vomitus an acid or alkaline?

Is gastric vomitus alkaline or acid?
Bile vomitus = alkaline

Gastric vomitus = acid
What acid base disturbance is seen with projectile vomiting?
Metabolic alkalosis
What is another name for aspiration pneumonia?

What gastric pH and volume increase the risk of aspiration?
Mendelson's syndrome.

increased risk of aspiration if pH is under 2.5 and volume is over 25 ml.
What causes serum alkaline phosphatase to increase?
A 3-fold increase in alkaline phosphatase in the serum is indicative of biliary tract obstruction.
What 4 symptoms may a person experience with pancreatitis?
1. Dehydration
2. Hypocalcemia
3. Hyperglycemia
0.1 unit change in pH will produce how much of a change in plasma K+?
Plasma K+ increases appoximately 0.6 mEq/L for each 0.1 units decrease in pH
What is the major intracellular buffer?
What is the anion gap?
Anion gap = major cations - major anions.

Na+ - Cl +HCO3

Normal range is 9 - 15 mEq/liter
Name the enzyme that breaks down cyclic AMP to 5'AMP?
Phosphodiasterase (PDE)
What is a dose response curve?

List 4 descriptive characteristics of a dose response curve?
a curve that depicts the relationship between the dose of a drug (x axis) and the resulting pharmacologic effect (y axis)

1. potency, slope, efficacy, and individual variability.
Describe how potency of a drug is depicted by a dose response curve?
The potency and receptor affinity are directly related. Left shift = less drug required = more potent.
What is drug efficacy? which feature of the dose response curve indicates the efficacy of a drug?
Efficacy is the intrinsic ability of a drug to produce a given physiologic or clinical effect. In other words, the maximal effect of a drug reflects its intrinsic activity, or efficacy. A drug's efficacy is depicted by the plateau of the dose-response curve.
Describe how the presence of a competitive antagonist would alter a dose-response curve of a drug? A noncompetitive antagonist?
The presence of a competitive antagonist (inhibitor) would shift the dose response curve to the right, with no change in efficacy (plateau) or slope. A noncompetitive antagonist would shift the curve right AND down, with a decrease in the slope of the curve.
What is the equation for volume of distribution?
Vd = Q / C

Quantitiy of the drug injected divided by plasma concentration
A substance with what clearance (large or small) and what volume of distribution (large or small) will have the longest half-time (T1/2) elimination?
half-time of elimination is greatest if:
Vd = large and C=small
(C = Vd / T1/2
Drugs that are absorbed from the GI tract must first pass through what organ? What is this called?

First-pass effect
During resuscitation, if venous acces cannot be obtained, what route of administration can result in high peak plasma levels? What drugs can be administered through this route?

NAVEL (narcan, atropine, vasopressin, epinephrine, lidocaine)
A patient with a known reaction to PCN is most likely sensitive to what group of antibiotics?
Cephalosporins (cefotaxime, cefoxitan, cefazolin)
Is there cross sensitivity among ester local anesthetics?

Between ester and amide local anesthetics?
There is cross sensitivity among ester LA. All have PABA.

There is NOT cross sensitivity between esters and amides.
Does ETCO2 increase, decrease, or remain unchanged when N20 is turned off? Why? what law applies?
ETCO2 decreases. When shut off, N20 rushes into the alveoli from the blood. The alveoli enlarge and gases that are present, including CO2, are diluted. Ficks law of diffusion applies.
How does N20 alter pulmonary vascular resistance and pulmonary artery blood pressure? Why?
N20 increases PVR and PA blood pressure especially with pulmonary HTN. N20 has a mild sympathomimetic effect.
Does N20 alone increase CBF or ICP?
In general, how much does N20 reduce the MAC of a volatile agent?
There is approximately a 1% reduction in MAC for every 1% N20 delivery
Which 2 volatile agents most decrease SVR?
Isoflurane and desflurane
How may an increase in ICP with isoflurane be prevented?
Hyperventilation during administration of isofluane.
Which volatile agent is LEAST likely to produce potentially dangerous increases in ICP if modest hypocapnia is present?
have volatile agents been shown to ihibit HPV? If so, what MAC?
Yes at high MAC's (1.0-1.5)
Which volatile agent has the highest incidence of causing a patient to cough?
Which volatile agent most depresses ventilation?

Least depresses ventilation?
Desflurane and enflurane most depress ventilation (Des = Depress)

Halothane least depresses ventilation.
Which volatile agents most depress the baroreceptor reflex, and which least depresses it?
Sevoflurane and halothane depress the baroreceptor reflex the most (no increases in HR with hypotension)

Isoflurane and desflurane depress the baroreceptor reflex the least.
What volatile agents are preferred for a patient with asthma? (2)
Sevoflurane and halothane
Water is added as a preservative to which volatile anesthetic?
Sevoflurane has water added as a preservative.
Which volatile agent is most degraded by soda lime?

Which is least degraded by soda lime?
Most degraded by soda lime = sevoflurane

Least degraded by soda lime = desflurane
What dysrhythmia is most commonly observed in the patient with a mitral valve lesion, either stenosis or regurg?
Where are the venous baroreceptors located?

How do they work?

What is the reflex called?
Venous baroreceptors are located in the right atrium and great veins.

They produce an increase in HR when the RA or great veins are stretched by increased vascular volume.

This is called the Bainbridge reflex.
What happens to HR during inspiration and during expiration in the spontaneously breathing patient?
HR increases with inspiration and decreases with expiration. During inspiration the pressure within the the thorax and venous return decreases.
What happens to arterial blood pressure during inspiration in the spontaneously breathing patient? Why?
Arterial BP decreases several mmHg during inspiration. with inspiration, pulmonary venous compliance increases and venous return to the left heart decreases.
Angiotensin I is converted to angiotensin II in what organ?
Pulmonary vasculature of the lung.
What percentage of total blood volume is found in the arterial system?

Venous system?

Arterial = 13%

Venous = 64%

Capillaries = 7%
Changes in what 4 factors may promote periphral edema?
1. decreased plasma osmotic pressure
2. increased capillary hydrostatic pressure
3. Increased interstitial proteins
4. Increased permeability in the capillary wall
What is the colloid osmotic pressure in mmHg of albumin?

How much does albumin contribute to the total colloid osmotic pressure of the plasma?
Colloid osmotic pressure of albumin is 22 mmHg.

Albumin is responsible for 80% of the total colloid osmotic pressure in the plasma.
What determines BF through an organ or tissue? This is an application of what law?
The two determinants of BF are pressure gradient and resistance.
BF = change in P / R

Ohms Law.
With hypercapnia, is there hypertension or hypotension?
Hypertension and hypotension may occur with hypercapnia. Hypercapnia causes direct depression of both cardiac muscle and vascular smooth muscle, but at the same time it causes reflex stimulation of the sympathoadrenal system
How does severe acidosis alter PVR and SVR/
Acidosis increases PVR and decreases SVR.
What is the venous saturation of coronary blood?
The venous saturation of coronary blood is 30%. The venous extraction of coronary blood is 70%.
Explain how an increase in coronary BF is achieved if the work of the heart increases? What is the most potent local vasodilator substance released by cardiac cells.
Usually changes in coronary BF are entirely due to changes in metabolism. Local factors are produced when metabolism increases and these local factors (adenosine) decreases coronary vascular resistance.
Arrange afterload, HR, and preload in order of greatest to least effect on myocardial oxygen consumption.
HR > Afterload > Preload
List 9 adverse effects of mannitol administration.
1. Pulmonary Edema
2. Rebound increase in ICP
3. Hypovolemia
4. Hypernatremia
5. Hyponatremia
6. Hyperkalemia
7. Acidosis
8. Dehydration
9. Acute hemodilution
Excessive brain dopamine appears to be associated with what disease?
Ventilatory depression is associated with which type of rigidity, decerabrate or decorticate?

Coma is associated with which?
Ventilatory depression is associated with decerabrate rigidity. Decerebrate is caused by extensive brain stem injury. Coma is associated with both decerabrate and decorticate.
A posterior left-sided rhizotomy would result in loss of what sensations from what sides (ipsilateral or contralateral)?
Loss of sensations carried in the anterolateral system (pain, temp, touch, tickle, itch) would be lost on the contralateral side. Loss of sensations carried in the dorsal lamniscal sytem (touch, pressure, position) would be lost on the ipsalaterl side.
Identify 2 metabolic factors that decrease seizure threshold.
1. Hypoglycemia
2. Hypocapnia
Where does calcium for skeletal muscle contraction come from?

For smooth muscle contraction?
Skeletal muscle- Calcium is released from the SR.

Smooth muscle - calcium diffuses into the cell from extracellular fluid.
Acetylcholine at the skeletal neuromuscular junction is hydrolyzed by what enzyme to what products?
Acetylcholine is hydrolyzed by acetlycholinesterase to choline and acetate.
What is the incidence of MH in adults? Kids?

What is the mortality rate for MH?
Adults= 1/50,000
Kids = 1/15,000

Mortality rate = 10%
Name 11 clinial manifestations of MH.
1. Hypercarbia
2. Tachycardia
3. Tachypnea
4. Hyperthermia
5. Hypertension
6. Dysrhythmias
7. Acidosis
8. Hyperkalemia
9. Muscle rigidity
10. Myoglobinuria
11. Hypoxemia
What response of MH is seen in kids?
Masseter muscle rigidity
How fast does temperature increase during an episode of MH?

At what body temperature should cooling of the patient with MH be stopped?
1-2 degrees C every 5 minutes

38 degrees C
What is the diagnostic test for MH?
The halothane-caffine contracture test remains the standard. unfortunately the test is not very sensitive, as there are many false positives.
What lab value may help confirm the diagnosis of MH?
CPK elevation
What syndrome can mimic MH?
Neuroleptic Malignant Syndrome- but the mode of onset and recovery are very different.
What is the major surgical risk for a patient with myasthenia Gravis?
Post-operative respiratory failure
What 5 factors predict the need for post-op mechanical ventilation in a patient with myasthenia gravis?
1. Disease for over 6 years
2. Concomitant pulmonary disease
3. PIP under - 25 cmH20
4. VC less than 4 ml/kg
5. Pyridostigmine doses of over 750 mg/day
Lambert-Eaton myasthenic syndrome (LEMS) is characterized by what?
LEMS is characterized by proximal skeletal muscle weakness that typically affects the lower extremities. It is assocaited with small-cell carcinoma of the lungs.

The disease is due to a decreased release of ACh from antibodies directed at the VG calcium channel.
How does anticholisterase therapy alter muscle stregnth in a patient with lambert-eaton myasthenic syndrome?

in Myasthenia Gravis?
Muscle stregnth improves with anticholinesterase therapy in a patient with myasthenia gravis but is unaffected in a patient with lambert-eaton.
Where is ADH synthesized and released?
ADH is synthesized in the supraoptic and paraventricular nuclei of the hypothalmus. ADH is released from the posterior pituitary (neurohypophysis)
What 6 hormones of the anterior pituitary are controlled by negative feedback mechanisms?
Prolactin (PRL)
What is the cause of central diabetes insipidous (DI)?

What is the cause of nephrogenic DI?
Central DI results from failure to release ADH from the posterior pituitary.

Nephrogenic DI occurs when the renal tubules fail to respond to ADH
What are 5 S&S of DI?
1. polydipsia
2. polyuria (hypoosmotic urine)
3. Hypernatremia
4. Hypovolemia
5. Hypotension
What occurs in SIADH?

What are the symptoms?
Excessive reabsorption of H20 from the renal tubules secondary to increased levels of circulating ADH.

Symptoms: H20 retention, Na+ retention, hypoosmotic plasma
Which is released in greater quanities from the thyroid gland, thyoxine (T4) or tri-iodothyronine (T3)?

Which is more potent?
T4 = 97%

T3 = 3-7% (3-4 times more potent)
What is the best initial test of thyroid function?
TSH level
The parathyroid gland regulates what 2 electrolytes?
Calcium and phosphate
Does parathyroid hormone raise or lower serum calcium?

How is this effect achieved?
Parathyroid hormone increases plasma calcium by increasing absorption of calcium from the intestine, increasing reabsorption of calcium from the renal tubule, and increasing calcium reabsorption from bone.
Where is calcitonin released?
Calcitonin is a polypeptide hormone secreted from the parafollicular cells (C cells) of the thyroid gland. Calcitonin has a weak role in calcium homeostasis in the adult.
What is thyroid storm?

Name 6 S&S of thyroid storm.

When is it most likely to occur?
A severe exacerbation of hyperthyroidism or thyroxicosis due to sudden excessive release of thyroid gland hormones (T3 & T4) into the circulation.

S&S: Hyperthermia, Tachycardia, Hyperglycemia, Shock, Dehydration, CHF.

Most likely to occur 6 - 18 hours post op.
What does the exocrine pancreas secrete (2)?

What hormones are secreted by the endocrine pancreas?
Exocrine: Digestive enzymes and sodium bicarbonate

Endocrine: Insulin and Glucagon (by the islets of Langerhorn- beta cells=insulin and alpha cells is glucagon).
The pancreatic duct and the common bile duct unite to form what structure?
Sphincter of Oddi, which empties into the duodenum.
What tissues do not need insulin to utilize glucose (2)?
What is the effect of insulin on plasma glucose? Why does this happen?
insulin lowers plasma glucose by permitting transport of glucose through the membranes of skeletal muscle and fat cells.
How much cortisol is normally secreted from the adrenal glands? How much during stress?
Normal= 20 mg/day

Stress 200-500 mg/day
Release of hormones from what 2 endocrine glands is regulated exclusively by nerve activity?
Adrenal Medulla and posterior pituitary
What are chromafin cells?
Chromaffin cells of the adrenal medulla synthesize and release catecholamines (Epi, Norepi, Dopamine)
What is the percentage of epi and norepi normally released from chromaffin cells of the adrenal medulla?

in Pheocromocytoma?
80% EPI and 20% Norepi

In Pheocromocytoma- 80% NOREPI and 20% EPI
What is the final metabolic product of catecholamine metabolism?
VMA = Vanillylmandelic Acid is excreted in the urine - 80-90%.
What disease is associated with hypersecretion of aldosterone by the adrenal cortex?
Conn's Syndrome (primary hyperaldosterone)
What is the triad for pheocromocytoma?
tachycardia, diaphoresis, and headache
Why is excessive sweating one of the diagnostic symptoms of pheocromocytoma if sweat glands are innervated by sympathetic cholinergic nerve fibers?
Sweat glands can be stimulated by EPI and NOREPI circulating in the blood even though sweat glands do not have adrenergic innervation
Can the liver act as a resevoir for blood?

If so, how much blood?

What controls the resevoir functions of the liver?
Yes. The liver stores up to 500 ml of blood at any time. The resevoir function is dependent on vascular tone and vascular pressures, especially on the venous side. Intense SNS stimulation can result in expulsion of 400-500 ml of blood in a matter of seconds.
What percentage of CO goes to the liver?

What percentage of hepatic blood flow is provided by the portal vein and by the portal artery?
Hepatic blood flow = 25% of CO.

Portal vein supplies 75% of total hepatic blood flow.

Hepatic artery supplies 25% of hepatic blood flow.
What percentage of hepatic oxygen supply is provided by the portal vein?

By the hepatic artery?
Portal vein provides about 50% of total O2 to the liver.

Hepatic artery provides 50% of total O2 to the liver.
What determines blood flow through the hepatic artery?
Hepatic artery blood flow is determined by the driving pressure (MAP minus hepatic venous pressure) and intrahepatic vascular resistance (Ohm's Law).

After eating, hepatic artery flow is dependent upn metabolic demand.
What are 7 functions of the liver?
1. Storage and filtration of blood
2. Metabolic functions such as fat, carb, and protein metabolism
3. Secretion of bile
4. Storage of vitamins
5. Blood coagulation
6. Storage of Iron
7. Detoxification and excretion of drugs
What are 3 likely hematologic abnormalities seen in chronic alcoholics?
1. Thrombocytopenia
2. Leukopenia
3. Anemia
What is the most common hematologic disorder in the alcoholic? Why?
Megaloblastic anemia in 20% of alcoholics. malnutrition leads to folate and thiamine deficiency. The cardinal manifestation of folate deficiency is macrocytic (megaloblastic) anemia.
A chronic alcoholic is bleeding and awaiting surgery. What treatments might be tried to control the bleeding? (4)
The chronic alcoholic may have liver disease. Treatments include: platelet transfusion, Vitamin K, FFP, and Cryo
Treatment of post-op alcoholic withdrawal is treated with what?
A long acting benzodiazepine such as Librium (chlordiazepoxide).
Why is hepatic blood flow reduced in the patient with alcoholic cirrhosis?

What is the significance to the anesthetist?
In hepatic cirrhosis, the portal vein has decreased blood flow because resistance to flow in the portal vein is high. Consequently, hepatic blood flow and oxygen delivery are MORE dependent on hepatic artery flow than in the normal patient. The anesthetist should avoid situations that decrease hepatic artery flow and O2 delivery by optimizing arterial BP and avoiding hypotension.
What is the most common major complication of cirrhosis?
What is the basic event in the formation of ascites?
Portal hypertension (excessive hydrostatic pressure in the portal vein) promotes the formation of ascites. Na+ and H20 retention play a secondary role. The hyrdostatic pressure in the portal vein is normally under 10 mmHg.
What is the major cause of morbidity and mortality in the patient with cirrhosis?
Massive bleeding from gastroesophageal varices.
An increase in plasma alkaline phosphatase concentration is an indication of what problem?
Damage to bile duct cells- possibly secondary to biliary obstruction
Is albumin a reliable marker for acute hepatic dysfunction? Why or why not?
Albumin levels are NOT a reliable marker for acute hepatic dysfunction because of the long half-life of albumin. Albumin's half-life = 20 days. Albumin is a good indicator of CHRONIC hepatic disease.
What is the basic defect of porphyria?

Identify the hallmarks of an acute porphyria attack?
Porphyrias are metabolic disorders that affect the biosynthesis of heme.

Abdominal pain, N/V, autonomic disturbances with sweating, tachycardia, HTN, seizures, and muscle weakness. Attacks can be life threatening and neuro condition can be permanent.
Identify the 3 major renal processes.

Which 2 require energy (ATP)?
Filtration, reabsorption, and secretion.

Reabsorption and secretion require ATP hydrolysis.
What is the function of the countercurrent systems in the kidney?
The countercurrent multipliers (loop of Henle) and exchangers (vasa recta) allow the kidneys to adjust the osmolality of the urine. (dilute or concentrate urine)
List 3 factors that stimulate the release of renin.
1. Decreased renal perfusion (hemorrhage, hypovolemia, renal artery stenosis)

2. SNS stimulation (activation of beta-1 receptors)

3. Hyponatremia
Do moderate levels of angiotensin II have a greater affect on the affertent or efferent arteriole? What is the significance?
When angiotensin II is increased in response to hypotension or volume depletion, efferent arterioles are constricted to a greater extent. This action prevents decreases in GFR.
Which of the following drugs should you be most concerned about in a patient with chronic renal failue:
Digoxin, quinidine, vecuronium, or atracurium?
Digoxin because the elimination is primarily by the kidney (35% of the drug eliminated daily).
Administration of what 2 products will treat uremic bleeding if surgery is planned (assuming dialysis is not a feasible option)?
1. Desmopressin 0.3-0.4 mg/kg IV over 30 min

2. Cryoprecipitate
Is each of the following lab values likely to be increased or decreased in a patient with chronic renal failure:
Creatinine, BUN, Hemoglobin, pH, K+, Ca+
Creatinine = increased
BUN = increased
Hemoglobin = decreased
pH = decreased
K+ = increased
Ca+ = decreased
What lab value reflects nephrotic syndrome?
Proteinuria and hypoalbuminemia are the hallmark lab values for nephrotic syndrome.
What are 5 signs of acute glomerulonephritis?

What will urinalysis and a blood workup show?
1. Hematuria
2. Proteinuria
3. HTN
4. Edema
5. Increased plasma creatinine

Urinalysis will reveal red blood cell casts.
What drug class causes urinary retention and thus may interfere with urinary bladder studies?
Opioids cause urinary retention, mediated by Mu-1 receptors. Opioids cause a dyssynergia between the bladder detruser muscle and urethral sphincter because of failure of sphincter relaxation.
What is the best indicator of renal reserve?
Creatinine clearance
If you suspect renal dysfunction, how can you estimate severity?
Creatinine clearance is an estimate of renal dysfunction.

40-60 ml/min = mild impairment

25-40 ml/min = moderate impairment.

less than 25 ml/min = overt renal failure
State the specificity and sensitivity of the fractional excretion of sodium in distinguishing between prerenal azotemia and acute tubular necrosis (renal azotemia).
The sensitivity and specificity of fractional excretion of sodium of <1% in differentiating prerenal azotemia and renal azotemia are 96% and 95% respectively.
Where is erythropoietin made?

What stimulates its release?

What does it do?
The kidneys make 90% of the erythropoietin and the liver makes 10%.

It is released in response to hypoxia.

It stimulates bone marrow to produce and release RBC.
Where does breakdown of hemoglobin occur?

What are the breakdown products?
Hemoglobin breaksdown in the liver.

Iron and porphyrin are the breakdown products. Porphyrin is converted to bilirubin.
What is the most important determinant of blood viscosity?

How many more times viscous is blood than water?

Blood is 3 times more viscous than water.
What is the function of protein C in hemostasis?
Protein C is a vitamin K anticoagulant. Thrombin (IIa) activates protein C and promotes fibrinolysis by causing release of tPA from endothelial cells and by destroying tPA.
What substance breaks down fibrin?

Where does this substance come from?
Plasmin digests fibrin. Plasmin is formed when the plasminogen system is activated by tissue plasminogen activator (tPA)
What 4 physiologic compensatory mechanisms of anemia tend to restore tissue oxygenation in the anemic patient?
1. Decrease blood viscosity
2. Decreased SVR (dilation of peripheral vasculature)
3. Increase stroke volume
4. Tissue extracts more O2
What are 5 compensatory mechanisms to increase O2 delivery in chronic anemia?
1. Increase CO
2. Increase 2,3,DPG
3. Increase P50 (right shift)
4. Increase dissolved O2
5. Decreased blood viscosity
Megaloblastic anemia develops when there is a deficiency in what 2 substances?
Megaloblastic anemia occurs with either a lack of vitamin B12 or folic acid. Red blood cells fail to mature. large, immature erythrocytes cause megaloblastic anemia.
Aplastic anemia is due to what?
Aplastic anemia is due to lack of functioning bone marrow. The most common cause is chemotherapy drugs.
What kind of blood cells result in iron deficiency anemia?
hypochromic, microcytic RBC's are typically found in iron deficiency anemia. When the quantity of iron falls to very low levels, hypocromic (RBC with diminished Hg) and microcytic (small, spherical RBC) anemia results.
What causes hemolytic anemia?
Even though the number of RBC's formed is normal, the lifespan is so short that serious anemia results. causes of hemolysis are diverse and include abnormalities of RBC membranes hereditary spherocytosis), enzyme defects (glucose-6-phosphate dehygrogenase deficiency), and abnormal Hg (sickle cell disease).
What 2 drugs should be avoided in a patient with glucose-6-phosphate dehygrogenase deficiency? Why?

What segment of the population has this deficiency?
Nitroprusside and prilocaine should not be given. These individuals are vulnerable to cyanide toxicity.

1% of the black population
What disease results from the defective rate of production of either alpha or beta globin strands?
The consequence of impaired synthesis of alpha or beta globin strands results in thalassemia (alpha or beta).
Are patients with sickle cell trait heterozygous or homozygous for Hgb-S?

Are patients with sickle cell anemia heterozygous or homozygous for Hgb-S?

What hematocrit is typically seen?
Sickle cell trait = heterozygous

Sickle cell anemia = homozygous. Hct = 18-30%.
What percentage of black americans have sickle cell trait? Sickle cell anemia?

What percentage of total Hgb pool is hemoglobin-S in a patient with sickle cell anemia?
Trait = 8 -10 %
Sickle cell anemia = 0.2 - 0.5%

Greater than 70% (70-98%) of total Hgb is hemoglobin-S
By what physiologic mechanism does hemoglobin-S alter the RBC?
The partial pressure of O2 is low and Hgb-S releases O2 and Hgb-S molecules attach to each other to form aggregates. This aggregation (polymerization) of Hgb-S, which occurs because of the substitution of valine for glutamic acid, results in deformation of the RBC into a sickle shape.
Whay are patients with sickle cell disease anemic?
Anemia results because RBC's are destroyed faster (10-15 days life-span as opposed to the normal 120 day life-span) than they can be produced. Hct is generally 18 - 30%.
What is the strategy for preventing sickling in a sickle cells patient?
Keep the patient warm, hydrated, on O2, maintian high CO, and avoid stasis.

Sickling occurs when Hgb-S is exposed to low O2 concentrations and crystals form which damage cell membranes, resulting in serious anemia.
The major goals for anesthesia of a patient with sickle cell anemia is to avoid what 4 conditions?
Avoid conditions that might promots low-flow states. Specifically, avoid:
1. hypo or hyperthermia
2. even mild hypoxemia
3. hypotension
4. hypovolemia
Must FFP be ABO compatible for administration?

If so, what is the universal donor?

AB is the universal donor.
FFP contains all procoagulant factors except platelets. Which factors are most abundant?
Factors V and VIII
What do fibrin split products assess?
Fibrin split products assess how fast fibrin or fibrinogen is breaking down.
In what disorder is the breakdown of fibrin or fibrinogen increased?

Briefly deascribe this disorder.
Fibrin split products are increased in disseminating Intravascular Coagulation (DIC).

DIC is an excess (pathologic) form of fibrin breakdown (fibrinolysis) that occurs in response to ncreased clot formation.
What 4 findings suggest DIC?
1. Thrombocytopenia
2. Prolonged PTT
3. Prolonged thromboplasting time (TT)
4. Reduced serum fibrinogen (or increase fibrin split products)
Partial thromboplastin time (PTT) monitors what pharmacologic agents?

Normal aPTT is less than how many seconds?
PTT assesses the adequacy of anticoagulation produced by heparin.

Normal aPTT is normally under 35 seconds (25-35 seconds = range)
What is the INR?
International Normalization Ratio is the ratio of the patient's PT to a control PT obtained by a standard method. INR allow practitioners to see if a dose of coumadin given is adequate for the condition being treated.
State what bleeding time assesses?

What is normal bleeding time/
Bleeding time assesses the quality and quantity of platelets.

Normal bleeding time = 3 - 8 minutes.
Significant bleeding occurs when a platelet level falls below what level?

Spontaneous bleeding occurs when a platelet level falls below what level?
Significant bleeding = PLT below 50 K

Spontaneous bleeding = PLT below 20 K
What herbal medications may increase bleeding?

How long should they be discontinued before surgery?
Garlic, Ginseng, Ginko. G's = Bleed.

They should be discontinued 2 weeks before surgery.
What is a carcinoid tumor?

What is the primary substance released?
Tumor within the GI tract, especially the appendix. These tumors release Serotonin (primarily- in 50% of the tumors), and other substances (bradykinin, histamine, prostaglandins, kallikrein)
Why are symptoms of a carcinoid tumor generally not seen? When are they seen?
Compounds released by tumors located in the intestinal tract are generally metabolized during the first bypass through the liver. Symptoms are seen with excessive hepatic metastases or when the tumor is not located in tissue drained by the portal system.
Identify the 2 types of acquired immunity.
Acquired immunity is the result of lymphocyte activity and is classified into humoral (B-lymphocytes) and cell-mediated (T-lymphocytes) immunities. B-lymphocytes is named because it was found in the Bursa of Birds. T-lymphocytes mature in the Thymus gland
Which lymphocytes are the sources of Ig?

List 5 immunoglobulins in the serum.

What percent of total serum proteins are immunoglobulins?
Mature B-lymphocyte plasma cells are the sourcemof the gamma globulin known as immunoglobulin.

GAMED- IgG, IgA, IgM, IgE, IgD

Immunoglobulins account for 20% of serum proteins.
What class of antibodies are produced in an anaphylactic reaction (type I hypersensitivity reaction)?
IgE antibodies are produced and attach to mast cells. When the person is re-exposed to the drug or volume expander, mast cells release their contents (Leukotrienes, histamine, prostaglandins, kinins, platelet activating factor) which causes the allergic respons (Bronchospasm, etc).
What is an anaphylactoid reaction?
An anaphylactoid reaction resembles an anaphylactic reaction but not not involve IgE. The drug or volume expander triggers the mast cells to release their contents without using IgE.
What are 2 sources of endogenous histamine and heparin?
Basophils and mast cells.
Does dextran trigger an anaphylactic or anaphylactoid reaction?
Dextran produced an anaphylactoid reaction.
List the 5 causative agents involved in anaphylactic reactions.
From greatest to least:
1. NMB (60%)
2. Latex (17%)
3. Antibiotics (15%)
4. Colloids (4%)
5. Hypnotics (3-4%)
What are 4 effects of acidosis of CNS function?
1. Depressed neuronal activity
2. Increased CBF and ICP
3. Decresed CPP (due to increased ICP)
4. Increases seizure threshold.
The kidneys excrete H+ a what 2 types of acid?
1. Titratable acids (H2PO4)

2. Ammonia ions (NH4+)
Can renal compensatory responses to chronic respiratory acidosis or alkalosis restore pH to normal?

Can ventilatory compensatory responses to chronic metabolic acidosis or alkalosis restore pH to normal?
Yes, sometimes.

A 70 kg adult has how many liters of body water? What percentage?

What fraction of total body water is found in the extracellular space?
42 liters. 60% of total body water.

1/3 (33%) or 14 liters is in the extracellular space.
In normovolemia, the rate of IV fluid administration must be adjusted to ensure how much urine output per hour (ml/kg/hr)?
At least 0.5 ml/kg/hr
Sodium salts represent what percent of all electrolytes in the extracellular fluid?

Sodium concentration is regulated by what 2 factors?
About 90%

Thirst and ADH
What hormone regulates osmolality?

What hormone regulates sodium concentration?


Aldosterone regulates the "amount" of sodium, not concentration. Aldosterone regulates VOLUME.
Which hormone acts faster to change serum sodium concentration, ADH or aldosterone?
ADH begins working in 5-10 minutes. Aldosterone begins working in 30-45 minutes and would take 2-3 days for aldosterone to correct a volume problem.
At what sodium level will a patient begin to see signs and symptoms of hyponatremia?

How is it treated?
120 mEq/L is the boarderline for severe reactions of hyponatremia.

Tx: diruretics and hypertonic saline
What are 8 S&S of hyponatremia?
1. Arrhythmias
2. Hypotension
3. Pulmonary Edema
4. Edema
5. Mental status changes
6. Muscle cramps
7. Weakness
8. Myoclonia
List 8 ways of treating hyperkalemia.
1. Calcium gluconate (10-30 ml IV)
2. Glucose/insulin (5-10 units RI per 25-30 g of glucose.
3. Sodium Bicarb (1-2 amps)
4. Diruretics to increase renal excretion.
5. Kayexalate (potassium exchange resins
6. Hemodialysis
7. Hyperventilate (alkolosis)
8. Beta-2 agonists (albuterol)
How much is plasma K decreased for each 10 mmHg reduction in PaCO2?
0.5 mEq/L
What 6 physiologic functions require calcium?
1. Action potentials in cardiac and smooth muscle
2. Blood coagulation
3. Bone formation
4. Muscle Contraction
5. Membrane excitability
6. Neurotransmitter release
What 2 electrolyte changes occur in the extracellular fluid with hyperventilation?
Hypocalcemia (inonized only) due to more calcium is bound to proteins in alkalosis.

Hypokalemia due to K+ shifting into cells in alkalosis.
List functions of magnesium.
Mag is an intracellular cation that functions as a cofactor in many enzyme pathways. It is important to:
1. Regulate Na/K pump
2. Regulate Adenyl cyclase
3. Regulate Calcium channels
4. Antagonizes calcium
5. Controls threshold
6. Stabilize membranes
7. Regulation and release of ACh
Which ion both resembles and antagonizes calcium?
magnesium acts like calcium in that it is a membrane stabilizer.

Mag also antagonizes some actions of calcium. For instance, mag causes vasodilation because it is an endogenous calcium channel blocker. Mag aslo antagonizes the calcium-stimulated release of neurotransmitter.
List 3 S&S of Hypermagnesemia.
1. Coma
2. Hypoventilation
3. Hypotension
What are 3 causes of Hyperphosphatemia?
1. Massive cell lysis (chemo)
2. Excessive Phos intake (laxatives)
3. Decreased Phos excretion (renal failure)
There are 4 modes of heat loss. Name and rank the modes from most to least route that contributes to heat loss
Radiation > Convection > Evaporation > Conduction


40% - 30% - 20% - 10%
Which route does a burn patient lose the highest percentage of body heat?

(Waugaman, page 635)
For each 1 degree C decrease in temp, metabolism decreases by what percent?
From 37 degrees C to 30 degrees C, metabolism decreases 7% for each degree centigrade.
During a procedure, a patient becomes hypothermic. What arrhythmia is likely?
Hypothermia prolongs the refractory period of excitable tissues, which can lead to Bradycardia. This can lead to an AV block or eventually VF.
Hypothermia alter SVR and CO?
Hypothermia is associated with increased SVR and myocardial depression (decreased cardiac output).
Identify 6 physiologic disturbances of hypothermia.
1. OxyHgb curve is shifted L- affinity for O2 is increased
2. Shivering increases O2 demand by 400-500%
3. Slowed metabolical dependent processes and drug biotransformation
4. Decreased GFR
5. CND depression
6. cardiac rhythym distuirbances - Bradycardia and PVC
Why will hypothermia decrease ventilation?

Why will hyperthermia increase ventilation?
CO2 production decreases with hypothermia and increases with hyperthermia. CO2 provides central respiratory drive.
What disorder is associated with small cell lung carcinoma (oat cell carcinoma)? (3)
2. Ectopic corticotropin secretion
3. Lambert-Eaton Myasthenic Syndrom (LEMS)
How would you expect a patient with small cell carcinoma (oat cell carcinoma) to respond to NMB agents?
They will exhibit an increased sensitivity to Succs and NDMB.
What is the volume or capacity that does NOT change in the obstructive pulmonary disease patient?
There is no change in tidal volume.
What are the normal parameters for:
FEF 25-75/MMEF?
FVC = 5 liters
FEV1 = 4 liters
FEV1/FVC = 0.8
MMEF 25-75 = 4.7 L/sec or 280 L/min
What test best assesses early stages of COPD?
MMEF 25-75 (midmaxillary flow)
How would you assess the respiratory reserve during the pre-op period? (3)
1. Exercise tolerance
2. Vital Capacity (best)
3. ABG
What is normal MMEF 25-75 for a 70 kg patient?
4.7 L/sec or 280 L/min
Pulmonary function testing reveals what changes in the patient with COPD?
FEV1 = decreased
FEV1/FVC = decreased (below 0.7)
TLC, FRC, RV are increased
MMEF 25-75 = decreased
A patient has an FEV1 of 1.8 and and FVC of 4.2. What is the problem and why?
The patient has obstructive disease. Obstructive disease shows normal or near normal FVC but low FEV1 and a low FEV1/FVC (under 0.7)
What dynamic spirometry values would place a patient in the moderate risk category for post-op pulmonary complications?
FEV1 = 1-2 L
FVC is < 50% predicted
FEV1/FVC > 35% and <50% predicted
MMEF 25-75 < 50% predicted
What EKG lead best detects ischemia resulting from occlusion of the left circumflex artery? What part of the heart is supplied?
I, aVL, V5-V6.

Lateral wall is supplied by the Left circumflex
What EKG lead best detects ischemia resulting from occlusion of the left coronary artery? What part of the heart is supplied?
Leads I, aVL, V1-V4.

The anterior wall is supplied by the LCA
What EKG lead best detects ischemia resulting from occlusion of the left anterior descending branch of the LCA? What part of the heart is supplied?

the left decending branch of the LCA supplies the anteroseptal wall
What is the characteristic EKG change with Digitalis?
Downsloping of the ST segment
Which is the best lead for detecting arrhythmias? Why?
Lead II because it has large P waves.
What are 3 characteristic EKG changes with hyperkalemia?
1. Prolonged PR interval
2. Widened QRS
3. Peaked T waves
A patient is hypokalemic. What change in HR may be seen?
There is increased automaticity of atria and ventricles, reflecting rapid rate of spontaneous phase 4 depolarization. Thus, HR increases.
What are 3 characteristic EKG changes seen with hypocalcemia?
1. Prolonged QT
2. Increased ST duration
3. Flat or inverted T waves
What are 3 characteristic EKG changes seen with hypercalcemia?
1. Short QT
2. Slight prolonged QRS
3. Widening of T wave
A diphasic P wave is characteristic of what condition?
Atrial hypertrophy, particularly of the left atrium.
What are 2 causes of ST segment depression?

What are 2 causes of ST segment elevation?
ST depression = subendocardial ischemia or infarct.

ST elevation = TRANSMURAL ischemia or infarct.
What is the most important plasma protein for binding of drugs?
What is the most important determinant for the buildup of IV anesthetic in a given tissue?
Blood flow to the tissue
Besides blood flow, what are 2 other factors that determine the amount of IV anesthetics going into and out of a tissue compartment?
Besides blood flow, 2 other determinants are lipid solubility and ionization in plasma
Xanthines (aminophylline, theophylline) have what action, in adition to inhibiting the breakdown of cAMP?
Xanthines inhibit the interaction of adenosine with its purinergic receptor, leading to increased NOREPI release from nerve fibers. Adenosine normally inhibits the release of NE from nerve.
In general, how much does N20 reduce the MAC of a volatile agent?
There is approximately a 1% reduction in MAC for every 1% of N20 delivery.
N20 is turned on and held at the same concentration for 6 hours. At 6 hours, is the uptake of N20 increasing, decreasing, or remaining unchanged?
N20 equilibrates with all tissues within 6 hrs, so uptake of N20 remains unchanged at this time. The amount of N20 inhaled essentially equals the amount exhaled.
Rank common inhaled agents from greatest to least in terms of PONV.
N20 > Des = Sevo = Iso
What are 2 detrminants of pulse pressure? What changes increase pulse pressure?
Stroke volume and arterial compliance. Pulse pressure increases when either CO increases or arterial comliance decreases.
What is the function of the capillaries? (name 5)
Capillaries allow exchange of:
1. O2
2. Fluid
3. Nutrients
4. Electrolytes
5. Hormones
Describe the effect of hypercapnia on the cerebral vasculature and on systemic vasculature.
Hypercapnia causes dilation of both the cerebral and systemic vasculature. Increased CBF and decreased SVR are seen.
How does hypercarbia affect pulmonary vascular resistance?
PVR increases in response to hypercarbia. This vasoconstrictor response is the opposite of what is observed in the cerebral and systemic vasculature.
What is normal range for coronary perfusion pressure?

How is it calculated?
60 - 160 mmHg

Coronary PP = aortic DP minus LVEDP
How are volatile agents carried in the blood?
What is measured by the blood:gas partial coefficient?
The B:G partial coefficient is a measure of blood solubility
Speed of induction and speed of emergence are related to what property of an inhaled anesthetic?
The speed of induction and emergence are INVERSely related to blood solubility. Thus, the lower the B:G partial coefficient, the faster the induction and the faster the emergence.
If the B:G coefficient is large, is the uptake of agent by the blood slow or fast?
Is the onset slow or fast?
Is the rise of the FA/FI slow or fast?
An inhalational agent with a large B:G coefficient is highly blood soluble. Hence, uptake by the blood is fast, but the speed of onset and the rise in FA/FI is slow.
For a volatile agent that is poorly blood soluble, (small B:G), is the uptake of the agent by the blood slow or fast?
Is the onset slow or fast?
Is the rise of the FA/FI slow or fast?
For poorly soluable agents, the uptake is slow.

The speed of onset is fast.

The rise in FA/FI is fast.
Brain uptake by anesthetic agents depends on what 4 factors?
1. Blood solubility
2. Cardiac output
3. Alveolar ventilation
4. Inspired concentration
What are 3 ways to quicken the process of equilibrium between alveolar and inhaled volatile anesthetics?
1. Increase inspired concentration
2. Second gas effect
3. Increased alveolar ventilation
What is the oil:gas partial coefficient for:
Sevo = 53.4
Des = 18.7
Iso = 90.8
N20 = 1.4
Halothane = 224
What is the significance of the oil:gas coeffecients for inhaled agents?
The O:G coefficient is a measure of lipid solubilty. Agents with high O:G are more lipid soluble and hence are more potent (and have smaller MACs)
What are the vapor pressures of:
Halothane = 244 mmHg
Des = 669 mmHg
Sevo = 170 mmHg
Iso = 240 mmHg
List volatiles in order of vapor pressures from lowest to highest.
Sevo < Iso < Halothane < Des
What 3 renal changes are associated with administration of volatile anesthetics?
1. Decrease in renal blood flow
2. Decrease in GFR
3. Decrease in urine output
Where and how are volatile anesthetics metabolized?
Volatiles are metabolized in the liver by the cytochrome P-450 system. (AKA mixed-function oxidases)
What is the name of the metabolite responsible for the acute hepatotoxicity that may be caused by halothane?
in susceptible individuals, an oxidative trifluoroacetyl metabolite of halothane may be produced. This may evoke production of neoantigens against hepatocytes.
Reductive liver metabolism occurs with halothane under what condition?
Are iso, des, and sevo metabolized by oxidative or reductive processes?
Which inhalational aent has no halogen?
N20 is the only agent without a halogen
Which volatile agents are susceptible to degradation to carbon monoxide in a CO2 absorber?
Desflurane can be degraded in a CO2 absorber into carbon monoxide, potentially promoting carboxyhemoglobin
What happens to the onset of action, duration of action, and elimination of thiopental in a patient with acidosis? Why?
Becasue thiopental is a weak acid, more drug in un-ionized in acidosis (acid + acid = unionized). Therefore, onset of action will be faster, duration will be shorter due to redistribution, and elimination will be slower.
What are the CV effects of induction doses of thiopental?
In normovolemic patients there is a mild and transient fall in BP due to peripheral vasodilation. Vasodilation of capacitance vessels cause a decrease in venous return and potentially a decrease in CO. HR may increase as a reflex.
Do induction doses of barbituates cause enzyme induction?
No. Induction doses of barbs do not alter post-op liver function. 2-7 days of sustained administration of barbituates is required for enzyme induction.
Does an induction dose of thiopental ordinarily obtund laryngeal reflexes?
No. laryngeal reflexes are not greatly depressed.
Where do barbituates work?
Barbituates produce sleep by depressing conduction through the reticular activating system (RAS).
What class of anesthetic agents may actually cause hyperalgesia?
Barbituates such as mexohexital and thiopental sometimes cause an antianalgesia effect.
What is the elimination half-time of thiopental?
11.6 hours
The use of barbituates is absolutely contraindicated in which 2 disease states?
1. Asthma
2. Porphyria
(also not mentioned - Siezure disorder?)
Rank opioids in order from most to least lipid soluable.
Sufentanil >> Fentanyl >>> Alfentanil >>> Meperidine > remifentanil > morphine
What effect do opioids have on the CO2 dissaciation curve?
If respiratory depression occurs, PaO2 decreases, and the CO2 curve shifts to the right.
Contrast spinal and supraspinal analgesia.
With spinal analgesia the perception of pain is decreased.

With supraspinal analgesia the patient's response to pain is altered. ("i feel pain but I don't care")
On what receptors do spinal opioids work to produce spinal analgesia?
Mu 1, Mu 2 (PRIMARILY), kappa, and delta receptors of the spinal cord and brain.
In addition to spinal and supraspinal analgesia, stimulation of mu-1 receptors elicits what 6 responses?
Mu-1 receptors produce:
1. Euphoria
2. Miosis
3. bradycardia
4. Hypothermia
5. Urinary retention
6. Pruritis
In addition to spinal and supraspinal analgesia, stimulation of mu-2 receptors elicits what 3 responses?
Mu-2 receptors produce:
1. Depression of ventilation
2. Physical dependence
3. Constipation
In what 2 ways do epidural and intrathecal opioids produce spinal analgesia?
They diffuse into the substantia gelatinosa and:
1. combine with presynaptic opioid receptors and inhibit release of substance P
2. Combine with postsynaptic opioid receptors and decrease activity in neurons ascending in the lateral spinothalamic tracts.
At what anatomic sites do opioids work to produce spinal analgesia?
Opioids work in the substantia gelatinosa of the spinal cord and at several supraspinal sites including the periaqueductal and periventricular gray matter
What brainstem areas send action potentials to the substantia gelatinosa via the dorsalateral funiculus?
The periaqueductal and periventricular gray matter
Spinal cord gray matter is divided into how many lamina? Opioids work in which of these lamina? What is another name for this lamina?
The gray matter of the spinal cord was divided by Rexed into 10 lamina (I to X). Lamina II is the major site for the action of opioids. lamina II is also known as the substantia gelatinosa. (some sources say that the substantia gelatinosa is formed by Rexed lamina II and III)
How do opioids (except meperidine) produce bradycardia?
Opioids, with the exception of meperidine, produce bradycardia by stimulating the vagal nucleus in the medulla, which increases vagal impulses to the heart.
List 4 ventilatory effects of opioid administration.
1. Decrease respiratory rate
2. Decrease minute ventilation
3. Decrease ventilatory response to CO2 due to brainstem depression
4. Increase arterial CO2 tension
What are the endocrine effects of opioids?
High dose opioids reduce or block the metabolic stress response to surgery. They also stimulate the release of prolactin and growth hormone while depressing the release of ADH.
The opioid induced spasm of the sphincter of Oddi can be pharmacologically reversed by selecting one of which 3 agents?
1. Naloxone
2. NTG
3. Glucagon
The incidence of severe opioid induced skeletal muscle rigidity may be increased by addition of what inhalational agent?
Which opioid agonist has the smallest volume of distribution?
Alfentanil. It is eliminated faster (shorter half-time elimination) than all other opioids EXCEPT remifentanil because of its small volume of distribution.
Identify 5 opioid agonist-antagonists.
1. Pentazocine (Talwin)
2. Butorphanol (Stadol)
3. Buprenorphine (Buprenex0
4. Nalbuphine (Nubain)
5. Dezocine (Dalgan)
Opioid agonist-antagonists promote analgesia by working on what receptors?
Kappa (primarily) and delta.
Do opioids inhibit hypoxic pulmonary vasoconstriction?
List 4 common side effects associated with spinal administration of opioids?
1. Puritis (MOST COMMON)
2. urinary retention
3. N/V
4. Respiratory depression
Which opioid should NOT be given with a neuraxial technique? Why?
Remifentanil. The safety of the buffering vehicle (glycine) has not been determine.
Rank opioids relative to elimination half-life from shortest to longest assuming continuous infusion.
Remifentanil (shortest) << alfentanil < morphine < sufentanil < meperidine < fentanil (longest)
Which has a shorter duration of action, fentanyl or morphine when given as a bolus? As a continuous infusion?
fentanyl has a longer elimination half-life but clinical impression is that fentanyl has a shorter duration of action when a single bolus dose is given. When given as a continuous infusion, morphine has a shorter duration of action.
Name 3 opioid antagonists.
1. Naloxone
2. Naltrexone (longer acting narcan)
3. Nalmefene
Naloxone easily reverses what 3 actions of opioids?

Higher doses of naloxone are required to reverse what 2 opioid agonist actions?
Naloxone easily reverses pruritis, urinary retention, and N/V

higher doses are needed to reverse profound sedation and respiratory depression.
Rank opoiods from most to least potent.
Sufentanil > remifentanil > Fentanyl > Alfentanil > Morphine > meperidine
Which opioid is most lipid soluable?
What is the basic structure of fentanyl and meperidine?
Phenylpiperidine derivatives.
A heroin addict taking methadone presents for surgery. What is your anesthetic concern?
Withdrawal produced by drug cessation. Avoid using an opioid agonist-antagonist preoperatively.
What tissue has the greatest capacity to accumulate morphine after IV administration?
Skeletal Muscle
Why might BP decrease after administration of sufentanil?
Sufentanil may produce a dose-dependent decrease in HR, probably by stimulation of the vagal nucleus in the medulla of the brainstem, sufficient to decrease CO and lower BP. HR slowing after sufentanil administration is prominent.
What are 6 CNS actions of benzodiazepines?
1. Antianxiety
2. Sedative
3. Hypnotic
4. Anticonvulsant
5. Amnestic
6. Muscle relaxant actions
What is the extent of protein binding of diazepam, midazolam, and lorazepam in a helathy man?
diazepam and lorazepam are 98% protein bound.

Midazolam is 94% protein bound.
What is the half-time elimination of midazolam?
1.7 - 2.6 hours
When is midazolam soluble in H20?

Midazolam comes in solution of what pH?
Midazolam is H20 soluable when pH < 4.0

Midazolam is available in a solution with pH at 3.5
What is the reversal for benzodiazepines called?

What makes it unique?

What is the half-life elimination?
Flumazenil is a competative antagonist of benzos. No other sedative hypnotic drugs have a specific antagonist. The half-life elimination = about 1 hour.
Which benzo is used to treat alcohol withdrawal?
Librium (chlordiazepoxide) is a long acting benzo used to treat alcohol withdrawal.
What are 2 non-opioid induction drugs that are associated with the excitatory phenomenon during induction?
Methohexital and etomidate
How does ketamine produce dissociative anesthesia?
Ketamine casue a dissocciation between the thalamocortical system and the limbic system. Specifically, ketamine depresses neuronal function in parts of the cortex and the thalmus while simultaneously stimulating parts of the limbic system.
Ketamine is related chemically to which drug of abuse?
Phencyclidine (angel dust)
What are IV and IM induction doses of ketamine?
IV = 1-2 mg/kg

IM = 5 - 10 mg/kg
What additive is found in etomidate? What problem may this additive cause?
Etomidate is provided as an aqueous solution of 0.2% etomidate and 35% propylene glycol. Propylene glycol may cause pain on injection.
Which IV induction agent is admistered as a single isomer?
Etomidate. (D-isomer per valley)
What are 4 potential problems during recovery from etomidate?
1. Suppression of adrenocortical response to stress
2. N/V
3. Low plasma cortisol concentration
4. Depressed immune response.
In addition to metabolism in the liver, propofol undergoes an extrahepatic route of elimination. Where is this route?
The lungs are responsible for about 30% of the uptake and first-pass elimination after a bolus of propofol.
Is propofol a weak acid or a weak base?
Weak acid
Cocaine is an ester of what?
Benzoic acid
Which of the amides are least toxic?
What advantage does ropivicaine have over bupivicaine?
Ropivicaine dissociates from Na+ channels more rapidly than bupivicaine and is less cardiotoxic. Ropivicaine produces less motor blockade.
What is the range of pKa's of local anesthetics?

Local anesthetics are prepared as what kind of salts?
7.6 - 9.1

Hydrochloride salts
Which local anesthetic may precipate when alkalinized (when bicarb is added)?
Bupivicaine may precipitate when alkalinized so much smaller doses of bicarb are to be added if used at all (o.1 mEq/20 ml bupivicaine). For comparison, up to 1 mEq of bicarb may be added to each 10 ml of lidocaine.
Compare the frequency of hypersensitivity reactions to ester local anesthetics with the frequency to amides.
Hypersensitivity reactions after administration of esters are rare, but reactions to amides are even rarer. If it is suspected that a patient may be allergic, an amide local anesthetic is preferable.
What is para-amnobenzoic acid (PABA)?
PABA is a metabolic end product of ester metabolism. This metabolite mediates hypersensitivity to ester local anesthetics.
What are 4 minifestations of hypersensitivity to local anesthetics?
1. Localized edema
2. Uticaria
3. Bronchospasm
4. Anaphylaxis
What are the three most cardiotoxic local anesthetics in order from most to least cardiotoxic?
1. Bupuvicaine
2. Etidocaine
3. Ropivicaine
Why is it difficult to treat the cardiotoxic effects of bupivicaine?
Because bupivicaine is highly lipid soluble and dissociation from cardiac Na+ channels is slow, acounting for its exaggerated and persistent depressant effects on cardiac function.
What active metabolite of lidocaine can contribute to toxicity even when plasma levels of lidocaine are in therapeutic range?
What are 4 conditions that decrease the concentration or diminsh the activity of plasma cholinesterase and hence prolong the action of ester local anesthetics, succinylchole, and mivacurium?
1. Pregnancy
2. Liver disease
3. Atypical plasma cholinesterase
4. First 6 months of life
What antimicrobial preservatives are added to commercial preparations of local anesthetic solutions in multidose vials? Should these solutions be used in spinals or epidurals?
Paraben derivatives such as methyl paraben, ethyl paraben, and propyl paraben.

These solutions should not be used in spinals or epidurals due to potential cytotoxic (neurotoxic) effects.
Which local anesthetics are chiral drugs?
The pipcoloxylidide locals (mepivicaine, bupivicaine, ropivicaine, levobupivicaine) are chiral drugs because their molecules contain an assymetric carbon atom.
What are the 2 local anesthetics that are pure S enantiomers? What is the advantage?
1. Ropivicaine
2. Levobupivicaine

These S enantiomers produce less neurotoxicity and cardiotoxicity than racemic mixtures.
In general, what structural characteristic of local anesthetics determine lipid solubility and hence potency?
The total number of carbon atoms. In general, lipid solubilty (potency) is increased by increasing the total number of carbon atoms in the molecule.
What term defines the lowest concentration of local anesthetic that blocks impulse conduction along a nerve fiber?
The Minimum Blocking Concentration (Cm) is the lowest concentration of a local anesthetic that blocks conduction.
What 3 anesthetics are effective when applied topically?
Tetracaine, Lidocaine, Cocaine
Which local anesthetic has the longest half-time of elimination?
Why does local anesthetic that is absorbed into venous circulation initially have limited effects on organs (heart, brain, etc.) in the systemic circulation?
substantial uptake of local anesthetics occurs in the lung, which limits the amount of drug that reaches the systemic circuit.
Which local anesthetic has 0% protien binding?
Chloroprocaine does not bind to proteins (0% protein bound)
Which local anesthetic has the greatest protein binding?
Bupivicaine (95%)
Epinephrine does not significantly increase the duration of action of which 3 local anesthetics?
Bupivicaine, etidocaine, ropivicaine
In addition to protein binding, what other characteristic of local anesthetics contribute to duration of action?
Lipid solubility. The greater the lipid solubility, the greater the duration of action.
What is the optimal concentration of epinephrine in local anesthetics?
1:200,000 (5 mcg/ml)
What are 3 reasons epinephrine may be added to a local anesthetic for peripheral nerve blocks?
1. Prolong action of anesthesia
2. Decrease systemic absorption
3. Permits use of larger volumes of local anesthetics without increasing risk of systemic toxicity.
How does prilocaine convert hemoglobin to methemoglobin?
Prilocaine, an amide local anesthetic, is metabolized by orthotoluidine. Orthotoluidine is an oxidizing agent capable of converting hemoglobin to methemoglobin.
What may cause HR and or BP to increase in response to succinylcholine administration?
Succs stimulates nicotinic receptors at the autonomic ganglia. The succs-induced HR and/or BP reflects the ability of succs to mimic the normal efects of ACh at the autonomic nervous system ganglia.
How are the actions of succs terminated?

How are the actions of ACh terminated?
Succs is enzymatically hydrolyzed by plasma cholinesterase. ACh is hydrolyzed by true cholinestrase, which is found at NMJ as well as tissues innervated by the PNS.
Describe the 2 phases of succinylcholine metabolism.
Step 1: Succs is metabolized by pseudocholinesterase to succinylmonocholine + choline.
Step 2: Succinylmonocholine is metabolized by pseudocholinesterase to succinic acid +choline.
Is mivacurium contraindicated for use in a burn patient?
What does increased magnesium do to nondepolarizing muscle relaxants? How does this happen?
Non-depolarizing blockade is enhanced by high magnesium levels.
magnesium decreases ACh release from nerve terminals and decreases the sensitivity of the post-junctional membrane to ACh.
Does phenytoin augment or antagonize the effectiveness of NDMB's?
Phenytoin antagonizes NDMB's.
Does dantrolene enhance, antagonize, or not affect the action of sketelal neuromuscular relaxants?
Because dantrolene directly relaxes skeletal muscle (by diminishing the release of calcium from the sarcoplastic reticulum), dantrolene enhances the effects of NDMB and depolarizing muscle relaxants.
Does a pretreatment of NDMB increase, decrease, or not affect the dose of succinylcholine required to achieve the same depth of depolarizing blockade?
When a NDMB is given before succs to prevent fasiculations and muscle pain, the succs is less potent and has a shorter duration of action. The requirement for succs is increased.
What are 2 reasons neostigmine and pyridostigmine prolong succinylcholine induced muscle blockade?
1. Anticholinesterases, by inhibiting true cholinesterase, increase ACh concentration at the nerve terminal, which intensifies depolarization.
2. Anticholinesterases inhibit plasma cholinesterases (reversibly) and reduce the breakdown (hydrolysis) of succs.
Organophosphates are classified as what type of drugs? which is used clinically?
Organophosphates are irreversible cholinesterase inhibitors. Echothiophate is the only one used clinically.
What are 4 anticholinergic drugs used clinically to inhibit muscarinic receptors?
1. Ipratropium
2. Atropine
3. Glycopyrrolate
4. Scopolamine
Which anticholinesterase drug appears to act presynaptically as well as post synaptically?
Neostigmine. It facilitates release of ACh from the nerve terminal and breaks down cholinesterase leaving more ACh available.
Which intrathecal opioid has the fastest onset? Why?
Sufentanil. It is highly lipid solubale.
Which drug, fentanyl or morphine, when injected intrathecally or epidurally, is prone to cause late/delayed respiratory depression?
Morphine can cause late depression of ventilation because it is hydrophilic.
Early respiratory depression may occur with morphine, fentanyl, or both?
What is the most common side effect of spinal opioid administration?
naloxone will not affect which side effect associated with epidural morphine?
Clonidine, when administered in the epidural or the spinal space, produces analgesia without opioid side effects. How is this analgesia produced?
Stimulation of alpha-2 receptors by clonidine in the substantia gelatinosa of the spinal cord inhibits the release of substance P. Substance p diminishes transmission of pain action potential.
By what mechanism does cocaine alter sypathetic function?
Cocaine blocks reuptake of norepinephrine
Are the effects of ephedrine direct, indirect, or both?
Both direct and indirect. It triggers the release of Norepi from nerve terminals and acts directly on adrenergic receptors.
What are 8 possible adverse reactions with ephedrine administration?
1. HTN
2. Tachycardia
3. Arrhythmias
4. Pulmonary edema
5. Anxiety/Tremor
6. Hyperglycemia
7. Transient Hyperkalemia
8. Necrosis at IV site
List 4 relative precautions to the use of ephedrine.
Use cautiously in patients with:
1. HTN
2. Ischemic heart disease
3. Depleteion of catecholamines
4. Insomnia
What is the proposed mechanism for tavhyphylaxis associated with indirect-acting sympathomimetics such as ephedrine?
tachyphylaxis may develop because of depletion of neorepi from the postganglionic nerve terminals
What receptors are stimulated by dobutamine?

How does it affect the CV system?
beta-1 (primarilly) and some beta 2. it increases CO by improving SV and contractility with minimal increases in HR and BP. It only promotes small decreases SVR
Drugs that stimulate what receptor have both positive inotropic and chronotropic properties?
Drugs that stimulate beta-1 adrenergic receptors have both positive inotropic and chronotropic properties.
What may be the most important clinical use of isoproterenol?
Because it increases conduction through the AV node, isoproterenol may be used temporarily as a chemical pacemaker in complete heart block (third degree)
What kind of drug is ritodine and what is it used for?

What are 3 side effects?
Selective beta-2 adrenergic agonist used to relax the pregnant uterus.

Side effects:
1. Hyperglycemia
2. Hypokalemia
3. Tachycardia
How does phentolamine produce tachycardia?
Tachycardia reflects release of norepi from sympathetic post ganglionic nerve terminals owing to alpha-2 receptor blockade.
What are 5 side effects of beta-blockers?
1. Heart block
2. Worsening CHF
3. Bronchospasm
4. Coronary artery constriction
5. Inhibits insulin release
What are 3 manifestations of abrupt withdrawal of beta-adrenergic receptor antagonists?
1. Tachycardia
2. HTN
3. Possible angina
What are 6 contraindications for esmolol administration?
1. Bradycardia
2. AV heart blocks
4. Hypotension
5. Cardiogenic shock
6. Cardiac failure
What kind of drug is timolol? How is it used?
Timolol is a non-selective beta adrenergic receptor antagonist. It is applied topically to the eye to decrease ocular pressure. Systemic absorption from the eye is sufficient to provide side effects related to beta 1 and 2 receptor blockade.
What serious problem can arise in a patient with diabetes mellitus who is given a non-selective beta blocker?
In patients with DM, there is risk that beta-adrenergic blockade may mask the signs of hypoglycemia and delay its recognition.
What is the best indicator of cyanide toxicity?

What are 4 hallmark signs of cyanide toxicity?
Base deficit by ABG.

1. metabolic acidosis
2. Cardiac arrhythmias
3. increased venous O2 content due to inhibition of cytochrome oxidase and inability to use O2
4. Tachyphylaxis
Tachyphylaxis develops during nitroprusside administration. After turning off nitroprusside, how should cyanide toxicity be treated?
Give sodium thiosulfate (150 mg/kg IV) over 15 minutes. Thiosulfate acts as a sulfur donor and converts cyanide to thiocyanide.
What is the mechanism of action of milrinone and inamrinone?
The are selective phosphodiasterase III (PDE) inhibitors. PDE III is cAMP specific which will result in increased cAMP in cells. In the heart, increased cAMP will produce increased inotropy whereas in the smooth muscle of the vasculature, increased cAMP promotes smooth muscle relaxation, vasodilation, and thus decreased SVR. These drugs are termed inodilators.
What side effect occurs with inamrinone, but not milrinone?
Thrombocytopenia with long term therapy.
What are 3 signs of digoxin toxicity?
1. Atrial or ventricular dysrhythmias
2. Prolonged PR
3. GI disturbances (N/V/anorexia)
What are 3 systemic effects of glucagon administration?
1. Increased myocardial contractility
2. Relaxes smooth muscle in the GI tract (spincter of Oddi)
3. Promotes glycogenolysis
Albuterol, a beta-2 agonist, relaxes smooth muscle of the bronchi by increasing the intracellular concentration of what 2nd messenger?
Stimulation of beta-2 receptors increase the intracellular concentration of 2nd messenger, cyclic adenosine monophosphate (cAMP). cAMP promotes bronchodilation.
How does ketorolac work?
It inhibits prostaglandin synthesis by inhibiting the enzyme cyclooxygenase, which normally converts arachidonic acid to prostaglandins.
How does protamine work to reverse the action of heparin?

What is the dose for protamine sulfate?
Protamine is strongly basic. It combines ionically with strongly acidic heparin to produce a stable salt complex. Then, the action of heparin is neutralized.

Dose= 1.0 - 1.3 mg protamine for every 100 units of heparin. Give slow.
What is the reversal for coumadin?

What is the dose? What is the onset? How long will it take to return PT to normal?
Vitamin K reverses coumadin. (FFP may be used too)

Dose = 10-20 mg IV (takes 3-6 hours to begin and 4-24 hours to return PT to normal range)
When should the last dose of LMWH be given before surgery?
12 hours before sugery
After surgery, when should a heparin drip be restarted?
12 hours after surgery, even in high risk patients because of the risk of severe hemorrhage.
After a dose of LMWH, when can a neuraxial block be placed?
10-12 hours after a dose of LMWH
If a neuraxial catheter is placed, how long should you wait to pull a catheter if a dose of heparin is given? How long do you have to wait for the next dose?

If a dose of LMWH is given? How long do you have to wait for the next dose?
If heparin is given, wait 2-4 hours and normal PTT or ACT before pulling the catheter. Wait 1 hour after pulling for the next dose.

If LMWH is given, wait 10-12 hours before pulling the catheter. After pulling the catheter, wait 2 hours before the next dose can be given.
Drugs that antagonize what receptors increase pH and decrease gastric volume? Name 3 of these drugs.
Histamine-2 receptor antagonists (H2 blockers) raise gastric pH and decrease gastric volume.
1. cimetidine
2. ranitidine
3. famotidine
Which H2 blocker most inhibits CYP450?

Which H2 blocker has no effect on CYP450?

Which H2 blocker has weak effect on CYP450?
Most effects CYP450= cimetidine

No effect = famotidine

Weak effect = ranitidine
What is the quickest way to increase gastric pH?
Non-particulate antacids such as sodium nitrate have immediate increase in gastric pH. H2 blockers are more effective but take longer to work.
What drugs used in anesthesia have the potential for producing extrapyramidal symptoms?
Competative dopamine antagonists may produce serious extrapyramidal symptoms. These drugs are metoclopramide, compazine, and droperidol
What type of metabolic disturbance may furosemide promote?

Lasix causes increased delivery of Na+ to the distal tubules and collecting ducts which increases K+ and H+ secretion, leading to hypokalemia and metabolic alkalosis.

Acetazolamide may promote mild hyperkalemic metabolic acidosis.
Which diruetics can cause ototoxicity, especially in renal failure?
Loop dirutetics- furosemide. Most often happens when other ototoxic drugs are used too. It can damage cranial nerve VIII.
What type of drug is acetazolamide? How does it work? What can it cause?
Acetazolamide is a weak diruretic and works by inhibiting carbonic anhydrase. It is primarily used to decrease intraocular pressure and is administered to treat altitude sickness. It reduces the formation of aqueous humor in the eye. This drug may cause hyperkalemic metabolic acidosis.
Bleomycin is toxic to what body organ? Why?

Cisplatin is toxic to what organ? Why? How can you reduce the toxicity?
Bloemycin, an antibiotic/chemotherapy agent, is toxic to the pulmonary system. It is concentrated preferentially in the lungs because the enzyme that inactivates bleomycin, called hydrolase, is relatively deficient in lung tissue.

Cisplatin is toxic to the kidney because of retention of platinum. Hydration, mannitol, and lasix may be used to reduce the toxicity.
Doxorubicin is toxic to what organ?
The heart. 1/3 of patients develop EKG changes (ST, PVC, PAC).
Which 3 chemotherapy agents are potentially toxic to the liver?
Streptozocin (70%)
What is a tocolytic drug? What are 3 tocolytic drugs and doses?
Tocolytics are used to supress uterine contractility.
1. Ritodrine (0.5 - 1 mg/min)
2. Terbutaline (0.01 mg/min)
3. Magnesium Sulfate (1-4 G/hr)
What is phospholipase A2?

What drugs work on PLA2?
PLA2 is the rate limiting enzyme that catalyzes the liberation of arachidonic acid (AA) from membrane phospholipids. The liberation of AA is the first step in the production of luekotrienes, prostaglandins, and thromboxanes. Corticosteroids are PLA2 inhibitors.
How do "statin" drugs work?

What are the 2 most-feared side effects?
Statins act as inhibitors of HMG-CoA reductase, the rate limiting step in cholesterol biosynthesis. HMG-CoA reductase catalyzes the conversion of the substrate HMG-CoA to mevalonate. The resulting inhibition of cholesterol synthesis is accompanid by decreases (up to 60%) in LDL (bad) cholesterol.

2 side effects:
liver dysfunction and severe myopathy
Where is glycogen stored in the human body?

How long will glycogen stores supply glucose during starvation?
Glycogen is stored in the liver (100 grams) and the skeletal muscle (400 grams).

The gylcogen stores will supply up to 24 hours of glucose during starving conditions (12-24 hours has been cited)
Define density.
Density = Mass/volume
What effect does hypothermia have on gas solubility?
As liquid is cooled, more gas dissolves in liquid: therefore hypothermia will cause an increase in gas solubility.
What does Graham's Law state?

Give an example.
Graham's Law states that a gas diffuses at a rate that is inversly proportional to the square root of its molecular weight.

Example: Helium will diffuse faster than N20 because it is lighter.
What CNS symptoms will be seen by hyponatremia at the following levels:
120 mEq/L?
115 mEq/L?
100 mEq/L?
120 mEq/L = confusion, restlessness, delirium
115 mEq/L = EKG changes
100 mEq/L = v-Fib
Which of the following drugs would not exhibit a smaller VOD in the geriatric patient:
Diazepam. In the elderly, total body H20 decreases while total body fat remains the same. Thus, the VOD for H20 soluble drugs such as glycopyrrolate, succs, and gentamycin decreases while the VOD for fat-soluable drugs such as benzos, barbs, and volatile increases.
All of the following are potential reasons for delayed recovery from anesthesia in geriatrics EXCEPT:
-Decreased liver function
-Decreased kidney function
-Increased protein binding
-Increased body fat percentage
Increase in protein binding is correct. Elderly have decreased protein binding because protein synthesis decreases with age.
Why is ketoralac usually not given to laboring patients?
Because they inhibit uterine contractions and promote closure of the fetal ductus arteriosis.
When would you see inspiratory stridor as opposed to expiratory stridor?
Inspiratory stridor results from upper airway obstruction

Expiratory stridor results from lower airway obstruction
What position is indicated for a patient immediately post tonsillectomy?
The patient should be placed in tonsillar position, which consists of lateral or semiprone position with the head down to decrease the risk of aspiration of blood.
Breast Milk should be held how many hours before surgery?
4 hours
Elective surgery on an infant should be deferred until the baby reaches what age?
50 weeks postconceptional age.
What measures can be done to decrease the risk of spinal cord ischemia in a patient having thoracic surgery with closs-clamping?
1. Reduce cross-clamp time
2. maintain normal cardiac function
3. Higher perfusion pressures
4. Hypothermia
5. Drainage of CSF
Which of the following parameters would NOT be elevated in the obese patient:
-Chest wall compliance?
-Serum AST levels
-Alveolar ventilation
-Cardiac output
Chest wall compliance will not be elevated.
What is the ratio of fluid replacement to blood loss when using hetastarch?
What is the maximum dose of dextran 40 you could safely infuse in a 80kg patient over a 24 hour period?
20 ml/kg (1600 ml)
On a CVP waveform, What dose the A wave represent?
The C wave?
The V wave?
The x and Y decent?
A wave = atrial contraction

C wave = elevation of tricuspid valve during ventricular contraction

V wave = venous return against a closed tricuspid valve

X and Y decents = downward displacement of the ventricle during systole and opening of the tricuspid valve.
The robin hood effect of barbituates is also known as what?
Inverse steal phenomenon.
What is normal insulin production per day in the adult?
40 - 50 units
Which of the following enzyme tests is most specific for the liver:
ALT is primarily in the liver and the most specific for liver damage
Which of the following agents does NOT decrease CSF production:
Etomidate does not decrease CSF production. CSF production is decreased by acetazolamide, isoflurane, furosemide, corticosteroids, spironolactone, and vasoconstrictors
What 2 opioids would not be recommended for use in a patient with a history of epilepsy?
Meperidine and alfentanil. Alfentanil in small doses have been associated with activation of seizure foci in patients with epilepsy.
How do you treat droperidol induced extrapyramidal reactions?

Drpoeridol should be avoided in patients with that diseases?
Extrapyramidal reactions to droperidol can be treated with IV benadryl. The anticholinergic actions of benadryl produce beneficial effects in this situation.

Droperidol should be avoided with Parkinson's Disease.
What are 3 side effects of TCA's?
1. Anticholinergic effects (dry mouth, blurred vision, tachycardia, urinary retention, slowed gastric emptying, ileus, delerium)
2. Orthostatic hypotension
3. Sedation
What are 3 common side effects of clonidine?

Why is it not safe to abruptly discontinue clonidine?
1. Sedation
2. Bradycardia
3. Dry Mouth (xerostomia)

Abruptly discontinuing is unsafe because it can cause rebound hypertension in 8-36 hours after the last dose.
What 3 hormones are involved in rebound hypertension associated with the abrupt discontinuation of clonidine?
1. Renin
2. Angiotensin II
3. Catecholamines
How is cyanide produced?

What 3 reactions may cyanide ions undergo?
With high doses of nitroprusside, the ferrous iron of nitroprusside reacts with sulfahydryl groups in RBC's and release cyanide.

Cyanide ions may react in three ways:
1. Reaction with thiosulfate in the liver to form thiocyanide
2. Binding to tissue cytochrome oxidase, which interferes with normal O2 utilization
3. binding to methemoglobin to for cyanomethemoglobin
How do cyanide ions interfere with oxygen utilization at tissue cytochrome oxidase?
Binding of cyanide ions to tissue cytochrome oxidase uncouples oxidative phosphorylation, preventing the formation of ATP.
Why does hypokalemia enhance digitalis toxicity?
Hypokalemia allows binding of digitalis to the Na+-K+ ATPase pump in cardiac cells, resulting in excessive drug efect.
What are 3 clinical uses of glucagon?
1. Treatment of insulin induced hypoglycemia.
2. Relaxation of the intestinal tract and sphincter of Oddi
3. Positive inotropy effects for heart failure who is unresponsive to beta-1 agonists.
What are 6 side effects of glucagon?
1. Nause
2. Vomiting
3. Tachycardia
4. Hypoglycemia
5. Hypokalemia
6. Hypertension
Why should verapamil be avoided or used cautiously in a patient taking a beta blocker of digitalis/
Verapamil, in comination with a beta blocker or digitalis, can produce complete heart block.
Ipatropium works by blocking the production of what second messenger?
Blockade of the muscarinic receptor by ipratropium will lead to a decrease in IP3. In the absence of IP3, less calcium is released and smooth muscle tone is decreased.
What does aprotinin do? What is it used for?
Aprotinin inhibits the breakdown of fibrin. Aprotinin does this by inhibiting plasmin. Aprotinin is given to decrease intra-op blood loss during cardiac surgery.
What are 8 deleterious effects of methylene blue administration?
1. Destruction of RBC's
2. HTN
3. Urinary bladder irritation
4. Nausea
5. Diaphoresis
6. Inhibits nitrate-induced coronary artery relaxation
7. Interferes with pulse ox for up to 2 minutes
8. Causes hemolysis in those with glucose-6-phosphate dehydrogenase deficiency
What is the pH of a liter of H20?
7.0 at 24 degrees C
What agents used in anesthesia are weak bases?
All local anesthetics (minus benzocaine), all opioids, all benzos, etomidate, and ketamine.
Do drugs that are weak acids form salts with positive ions such as sodium or negative ions such as sulfate or chloride?
Weak acids form salts with positive ions (Na+, Mag, Ca+, K+). Sodium pentobarbital is an example.
Do drugs that are weak bases form salts with positive ions such as sodium or negative ions such as sulfate or chloride?
Weak bases form salts with negatively charged ions (chloride, sulfate,phosphate). Lidocaine hydrochloride and morphine sulfate are examples.
What is the name for 2 optical isomers mixed together in a solution?
Racemic mixture
During anaerobic metabolism, how many moles of ATP are formed from one mole of glucose?
During aerobic oxidation of glucose to water, how many moles of ATP are formed for each mole of glucose used?
The process whereby ATP is formed from ADP is called what?
Oxidative phosphorylation
What are the fat soluble vitamins?

What are the water soluble vitamins?
A, D, E, K

C and the B complex
Which amino acid is a precursor of nitric oxide (NO)?
One torr is how many mmHg?

One mmHg is how many cmH20?
One torr = 1 mmHg

One mmHg = 1.36 cmH20
Whose law applies to the diffusion of gases between a gas phase and a liquid phase?
Fick law of diffusion
What is vaporization?

What is heat of vaporization?

What is latent heat of vaporization?
Vaporization is the phase change from the liquid state to the gaseous state. Energy is required.

A liquids heat of vaporization is the number of calories (energy) needed to convert 1 ml of liquid into a vapor.

Latent heat of vaporization is more precisely defined as the number of calories needed to change 1 GRAM of liquid into a vapor without changing temperature.
What is critical temperature?
Critical temperature is the temperature above which a gas cannot be liquified, no matter how much energy is applied.
What is critical pressure?
Critical pressure is the minimum pressure necessary to liquify a gas at its critical temperature.
At what temperature in degrees Centigrade can oxygen be liquified?
The critical temperature of O2 = -119 degrees C. The temperature would have to be equal to, or less than -119 degrees C to liquify O2.
What happens when the vapor pressure of a liquid exceeds the total pressure in the gas phase?
The liquid boils
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