Metabolic Alkalosis

Question 1

metabolic alkalosis

Answer 1

*any process in which the pH of the body increases as a result of increased concentration of serum bicarbonate
*results in:
-high pH
-high bicarb
-high PaCO2 (compensation)

Question 2

metabolic alkalosis - clinical presentation

Answer 2

*often asymptomatic
*if symptomatic, commonly presents with:
-volume depletion (dizziness, fatigue, muscle cramps, lightheadedness when standing suddenly)
-hypokalemia: cramping, diffuse muscle weakness

Question 3

metabolic alkalosis - pathophysiology

Answer 3

*can result from:
1. loss of acid in the stomach (vomiting, nasogastric suction)
2. loss of hydrogen ions in kidney via use of diuretics
3. high aldosterone states (hyperaldosteronism)
4. excess intake of bicarb (antacids)

Question 4

chloride-responsive metabolic alkalosis

Answer 4

*corrected by administration of sodium chloride (normal saline)
*most common types of metabolic alkalosis
*causes include: GI loss of acid, diuretic-induced loss of acid

Question 5

metabolic alkalosis due to GI loss of acid

Answer 5

*vomiting or nasogastric suctioning → loss of stomach acid and retention of bicarbonate → alkalemia
*chloride-responsive
*urine Cl- is LOW ( < 10 mEq/L)

Question 6

metabolic alkalosis due to diuretic-induced loss of acid in the kidney

Answer 6

*loop diuretics (furosemide) → aldosterone-stimulated H+ ion secretion into the urine → loss of acid in the urine
*chloride-responsive
*urine Cl- is HIGH if the diuretic use is ongoing ( > 20 mEq/L)

Question 7

chloride-resistant metabolic alkalosis

Answer 7

*not corrected by normal saline (sodium chloride) administration
*due to an endocrine or renal tubular abnormality causing wasting of hydrogen ions

Question 8

metabolic alkalosis due to hyperaldosteronism

Answer 8

*increased aldosterone levels (from an adrenal tumor or adrenal hyperplasia) → stimulates hydrogen ion secretion in the intercalated cells of the collecting duct → loss of H+ in the urine
*chloride-resistant
*urine Cl- is HIGH ( > 20 mEq/L)

Question 9

metabolic alkalosis due to congenital tubular abnormalities

Answer 9

*Bartter, Liddle, and Gitelman syndromes can all cause hydrogen loss in the urine
*chloride-resistant
*urine Cl- is HIGH ( > 20 mEq/L)