Acid-Base Balance Flashcards

Terms Definitions
negatively charged ions
Metabolic Alkalosis=

High pH
Normal PaCO2
High HCO3
Normal HCO3-
22 to 28
Metabolic component of blood gases
Normal Paco2 level
35-45 mm Hg
Thiazide-like diuretics
chlorthalidone (Hygroton) metolazone (Mykrox, Zaroxolyn)
anion gap
difference between the concentrations of serum cations and anions, determined by measuring the concentrations of sodium cations and chloride and bicarbonate anions.
Normal valuses for O2 saturation is
Represents the metabolic component of acid-base balance
Initially expands and raises the osmolality of ECF Require frequent monitoring of Blood pressure Lung sounds Serum sodium levels
abnormally acidic
a blood PH below 7.35 is
water moves from a more dilute solution (of a solute) to a more concentrated solution (of the solute) through a membrane that is permeable to the solvent until the solution is equalized
The normal range for PaO2 is
80-100 mmHg
Acidosis that results from respiratory dysfunction is called?
Respiratory acidosis
Reflects the metabolic component of acid-base balance
bicarbonate level
Partial pressure of Carbon dioxide in arterial blood
mannitol (Osmitrol)
Crystalizes,so always use a filter! Give w/blood. Never give to someone who is dehydrated or has liver failure,or Heart failure! Emergency Drug! IV ONLY!
Metabolic Acidosis
pH low, HCO3 low
confusion, stupor, coma, ineffective respirations, DIARRHEA, dry flushed skin.
(used of solutions) having the same or equal osmotic pressure
antidiuretic hormone
ADH. hormone secreted by the posterior pituitary gland and also by nerve endings in the hypothalamus
The kidneys regulate pH balance by
altering HCO3 levels
what condition is caused by increases in CO2 in blood causing an increase in H+
respiratory acidosis
Metabolic Alkalosis Causes
1. Diuretic thearpy
2. Prolonged steriod therapy
3. Excessive loss of H+ - (a) Prolonged NG suctioning, (b) Excessive vomiting
Most plentiful buffers in the body, work inside and outside cells
protein buffers
Signs and Symptoms of Respiratory Acidosis
Rapid irregular pulse
Thiazide and Thiazide-like Diuretics Drug Effects
Lowered peripheral vascular resistanceDepletion of sodium and water (and potassium)
insensible water loss
water loss through the skin and lungs
What is a base?
a substance that dissociates to release hydroxide (OH-) ions or binds hydrogen (H+) ions- causes an increase in pH
what are some reasons for metabolic alkalosis
vomiting, fever, tachypnea
Nursing interventions for metabolic acidosis
restore blood volume and osmolarity
Correct HCO3 deficit
assess for and prevent electrolyte imbalances (Hyperkalemia) and protect from injury.
Responds to pH changes in minutes, but can only restore normal pH temporarily
Respiratory system
Potassium-Sparing Diuretics Drug Effects
Prevent potassium from being pumped into the tubule, thus preventing its secretionCompetitively block the aldosterone receptors and inhibit its actionThe excretion of sodium and water is promoted
milliequivalents per liter
mEq/L, number of grams of a specific electrolyte dissolved in 1 L of plasma.
Distinguish metabolic acidosis from respiratory acidosis on the basis of etiology (cause)
Respiratory Acidosis -lungs cannot remove excess CO2 (most common)Causes:- diseased lung- shallow breathingMetabolic Acidosis - excess of organic or fixed acids. Causes: -ingestion of too much alcohol (converted to acetic acid) -excessive loss of bicarbonate ions (diarrhea)- accumulation of lactic acid (exercise, shock)- accumulation of ketone bodies (diabetic crisis, starvation)- kidney failure

Replace bicarbonate and administer LR or NSS
Administer insulin and glucose to carry K+ back into the cell
Provide ventilatory support

Either d/t an excess of HCO3 or a decrease in hydrogen ion concentration
pH > 7.45
HCO3 > 26
What is the basic problem in respiratory alkalosis?
Hyperventilation leads to hyperexcretion of CO2. Low PaCO2 equates to low H+ and thus a high pH.
ABG results that indicate respiratory acidosis
Low pH and High paco2
Thiazide and Thiazide-like Diuretics Indications
Hypertension (one of the most prescribed group of drugs for this)Edematous statesIdiopathic hypercalciuriaDiabetes insipidus HF due to diastolic dysfunctionAdjunct drugs in treatment of edema r/t HF,hepatic cirrhosis, corticosteroid or estrogen therapy
What is respiartory compensation?
- pH changes outside of normal range causes changes in respiaratory rate that directly interact with the bicarbonate buffer system- addition of an acid, causes a left shift in equilibrium --> increases CO2 which stimulates an increase in respirations --> lowers CO2- with addition of an acid, respiratory compensation eliminates carbonic acid via releasing CO2- addition of a base causes a right shift in equilibrium which releases H+ and causes an decrease in CO2. Low CO2 depresses respirations causing CO2 levels to rise- when a base is added, respiratory compensation increases H2CO3 by retaining CO2
How can respiratory mechanisms compensate for a metabolic acidosis?
An increase in ventilation to increase excretion of CO2. This consumes H+ and raises pH. Note that change is enacted by a change in PCO2, characteristic of respiratory compensation.
What is the reaction time of the big three regulatory systems of acid-base imbalances?
buffers/immediately; Lungs/within minutes; Kidneys/within hours or days
What are the three types of buffering systems?
protein buffer system, phosphate buffer system, and carbon dioxide/bicarbonate buffer system
What should the nurse do for a respiratory alkalosis pt.?
Eliminate cause of hyperventilation, help person breathe more slowly and deeply (paper bag), if neurological problems is the cause, treat the primary problem.
Respiratory Alkalosis pH 7.44 or >, PaCO2<36mmHg, HCO3 N, K+<3.5 mEq/L
Hyperventilation, may be r/t Anxiety High altitude Pregnancy Fever Hypoxia Excessive tidal volume in ventilated patients Initial stage of pulmonary embolus
Describe how ammonia excretion by the renal tubule can lead to HCO3 generation.
- Renal tubule deaminate amino acid glutamine- the amino group picks up H+ to become ammonia (NH3) which is secreted into the urine- ammonia (NH3) acts as a base in the urine because it can pick up another H+ to become ammonium (NH4)- deamination of glutamine also produces new bicarbonate ions from keto acids that will be added back to blood to help restore the buffering capacity of blood
What do the lungs do to help the metabolic system if it has too little bicarbonate (low pH/acidosis)?
The rate of respirations increase.
What is the role of LDLs in the transport of lipids?
transport cholesterol from the liver to peripheral tissues
Give an example of ABGs that indicate respiratory compensation for metabolic acidosis.
pH below 7.35 Bicarbonate below 22 mEq/L and Paco2 below 35 mm Hg
How do the protein buffers keep the blood in the desired pH range?
they bind H+ when pH is too acidic (increase in H+ concentration) and release H+ when  pH is too basic (decrease in H+ concentration
how long do the lungs take to fix acid-base problems and is it a complete fix?
it takes hours and no it is not completely fix. close to normal but not quite
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