|What accounts for 80% of CVA's?||
Ischemic Cerebral vascular disease
|What is the most common site of atheroscelrosis in the brain?||
Proximal Internal Carotid Artery
|What is the treatment goal for the patient undergoing a CEA?||
To reduce the risk of recurrent stroke
|What artery branches off of the Brachiocephalic artery?||
Right common carotid artery
|Where does the Left common carotid artery branch from?||
Directly from the Aorta
|What do the common carotids bifurcate into?||
The internal and external carotid arteries
|What does the internal carotid artery branch into and supply?||
*Branches into the middle and anterior cerebral arteries
*Supplies the ocular globe via the opthalmic artery, and the cerebral hemispheres.
|What does the external carotid artery supply?||
The neck, face, scalp, oral, nasal cavities and meningies.
|What three nerves run in close proximity to the neck vessels?||
Recurrent Laryngeal Nerve (branch of vagus)
Vagus nerve (X)
|What does the carotid sinus contain?||
Contains baroreceptors or stretch receptors and carotid bodies.
|Where are the carotid sinuses located?||
Above the carotid bifurcation
|What happens when the carotid sinus is manipulated?||
Afferent impulses are sent to the vasomotor center via the glossopharyngeal nerve.
|What is the efferent response to carotid sinus stimulation?||
Vagal in nature causing bradycardia and possibly hypotension
|What two manifestations are responsible for carotid stenosis?||
Thrombus or Embolus
|What is the term that describes monocular blindness?||
|What is the definition for a Transient Ischemic Attack (TIA)?||
A neurologic event that resolves in less than 24 hours. Major strokes are preceded by TIA's
|What is the definition of a stroke?||
A neurologic deficit lasting >24 hours.
|What s/s would be present with a large embolus passing into the Middle Cerebral Artery?||
*Contralateral deficits that affect the face and upper extremity.
|What are the s/s of a large emboli traveling into the Anterior Cerebral Artery?||
*Effects the contralateral legs producing loss of motor and sensory function.
|How is asymptomatic carotid stenosis usually detected?||
As an incidental finding. A bruit can be auscultated in the neck.
|What are indications for getting a CEA?||
*Lesions greater than 70% with TIAs
*Severe ipsilateral carotid stenosis with mild stroke
*30-70% occlusion with ipsilateral symptoms
How long should a CEA be delayed after a CVA?
*Because of a 20 fold increase in the risk of intraoperative cerebral ischemia
|Is surgery performed on lesions that are 100%?||
*No, if collateral flow wasn't present around the 100% occlusion the patient would be dead.
|What nerves are at risk of injury when the carotid sheath is opened to expose the carotid artery (4)?||
*The Phrenic Nerve
*The Vagus Nerve
*Recurrent Laryngeal Nerve
How many units of heparin are typically needed to maintain an ACT>300?
|When will heparinization be needed?||
Following complete exposure of the common, internal and external carotid
|How are all three arteries (common, internal and external carotid) clamped and why?||
*Sequentially to minimize distal embolization
|What is the onset of heparin?||
|What is the half life of heparin?||
|How is the carotid dissected during the CEA procedure?||
*From the common carotid to the ICA distal to the area of plaque.
|How is the plaque freed from the artery?||
*It is endarectomized and feed from the artery
|How is the arteriotomy closed or repaired?||
*With a prosthetic patch and flow is restored.
|What is a medication and a diagnostic procedure that may or may not be performed at the end of a CEA?||
*Use of protamine sulfate
|Why is a shunt sometimes utilized during a CEA?||
*To minimize cerebral ischemia by reestablishing flow to the ipsilateral cerebral hemisphere during cross clamping.
|What pressure is measured and what parameters determine use of a shunt?||
*<60mmHg indicates the need for a shunt
What does a stump pressure <60 indicate?
What is the false positive rate of a stump pressure?
*Inadequate retrograde flow from the Circle of Willis.
|List complications of a shunt||
*Surgical field obstruction
*Air entrainment, embolism
*Create an intimal flap that can promote thrombus formation
*Plaque dislodgement during placement
*Blood loss from dislodgement
|What along with a through H&P should be considered Preop?||
*Cardiac clearance with complete history of past or present illness (MI, CHF, Angina, Valvular disorder, previous surgeries or interventions)
*Cerebral blood flow studies
*Vital signs with BP in both arms
*Blood Type & Screen
|What is the greatest cause of surgical mortality in a CEA?||
*1-4% related to Myocardial Infarction
|What is the greatest cause of surgical Morbidity in a CEA?||
*Intraoperative neurological event (Stroke)
|What are some other common co-existing diseases in the patient undergoing a CEA?||
*Past Hx of CEA
|What should be evaluated preop if this is the second CEA procedure? Why?||
*Vocal cord function may be evaluated to r/o Superior Laryngeal Nerve injury or paralysis
|What need to be thoroughly documented Preop in the patient undergoing a CEA.||
*Neurological Exam with residual effects of past CVAs
|Where should the arterial line be placed in the pt undergoing a CEA?||
*In the contralateral radial artery
|What are some things to consider when setting up the room for a CEA?||
*Arterial line set up
*Pressure line available for Stump pressure monitoring
*Standard monitors- 5 lead EKG
*Prepare for patient to possibly be turned away from anesthetist losing access to head and ipsilateral arm
*Possible intraop EEG, TCD, SSEP
*NO EKG leads under neck or head due to possible intra op angiogram
|What are two acceptable anesthetic techniques for a CEA?||
*Cervical plexus blockade (superficial and deep)
|Which anesthetic option (general or regional) is the most commonly utilized option?||
|List some advantages in using a GETA technique during a CEA||
*decreased patient movement
*length of procedure not a factor
|*What are some disadvantages with using GETA for a CEA?||
*More hemodynamic fluctuations
*Inability to assess neurologic function throughout procedure
List advantages of using cervical plexus blockade for a CEA
*Provision of better hemodynamic stability
*An awake patient available for immediate neurologic evaluation potentially decreasing the need for unnecessary intraoperative shunting
|What is the best neurologic monitor of the patient undergoing a CEA?||
*an awake patient
|What are some disadvantages of using regional anesthesia for the patient undergoing a CEA?||
*Technical difficulty of managing the airway of an ischemic event did occur
*Requires a quick surgeon comfortable with this technique
*Unable to provide cerebral protection
*Inability to control PaCO2/ABGs
*It requires a cooperative patient and a normal coagulation profile
|What are complications of regional anesthesia in the cervical region used for a CEA?||
*Horner's Syndrome d/t stellate ganglion being affected
|What are s/s of Horner's Syndrome?||
Ipsilateral ptosis, miosis, anhydrosis, squeaky voice
|Where should blood pressure be kept intraop during a CEA?||
*BP should be kept in the patient's high normal range in order to maintain cerebral perfusion (Ischemic areas may have lost autoregulation)
|How much fentanyl should be used during CEA?||
*5-7mcg/kg front loaded in order to avoid sedation upon emergence
|What are some pharmacological agents that should be used with caution during a CEA?||
*Ketamine should be avoided
*STP and propofol due to cardiac depression
*Desflurane d/t subsequent tachycardia associated with its use
|For a CEA induction should be.................||
*Slow and smooth allowing for endotracheal intubation without wide swings in MAP
|What should absolutely be avoided while artery is clamped? Why?||
*Some suggest increase in MAP 20% prior to and during clamping of common carotid
|What should absolutely avoided after artery repair in a CEA? What can occur if this happens?||
*Cerebral Hyperperfusion Syndrome (like a stroke when BP gets high)
|Where should fluids generally be kept during a CEA?||
|What is a normal EBL for CEA?||
|What are modifications that anesthesia can control that lower CMRO2?||
*Normocarbia (PaCO2 35-45)
|Why should hypothermia be avoided during a CEA and surgery in general?||
*Due to the leftward shift it causes in the oxyhemoglobin dissociation curve (makes it harder for oxygen to dissociate from hemoglobin), post op shivering, and coagulopathy
|What should you do if bradycardia ensues d/t surgical stretching of the baroreceptors?||
*Tell the surgeon
*Try to let the response extinguish itself
*Can localize with 1% lidocaine on field
*Treat if symptomatic
*Can give a small amount of robinol to increase HR
|Emergence from CEA should be...............||
*Slow, smooth and devoid of wide swings in MAP
*Avoid coughing and bucking on OET
*Can give lidocaine to attenuate laryngeal reflexes
*Fully reverse NDMR
|What should be checked after emergence from a CEA PRIOR to leaving the OR?||
*Quick neuro check of bilateral muscle strength and tongue movement before leaving the OR!
What medication should be ready for use during and after emergence of a CEA?
What medication should be used with caution?
*Antihypertensive medications should be ready
*Use analgesics carefully to avoid hypoventilation
|What is the most common cause of M&M postop in the CEA pt?||
|What is the second most common cause of M&M postop in the CEA patient?||
|List some causes of respiratory depression post op in the CEA patient||
*Malfunctioning carotid bodies, less sensitive
|What are the most common life threatening complications that can occur post op in the CEA pt?||
*Acute Carotid Occlusion
What does carotid hemorrhage present like?
What should be done?
*Wound enlargement, upper airway obstruction, and tracheal deviation
*Immediate control of airway
*Returned to OR for angiography and possible reexploration.
|What are the manifestations of carotid occlusion?||
Neurological status changes
|What are some causes of hemodynamic instability in the post op CEA patient?||
*Loss of normal baroreceptor function
*Hypoxemia and hypercarbia leading to increased intracranial pressure
|What is the goal for maintenance of MAP post op in the CEA pt?||
*At low normal range for the patient
|When should the baroreceptors normally reset themselves post CEA?||
*Within 12-24 hours
|What is an alternative method of intervention for carotid stenosis other than CEA?||
|What is the patient population that is considered for Carotid Stenting?||
The very high risk patients