Which of the following electrolytes are lost as a result of vomiting?
A. Bicarbonate and calcium
B. Sodium and hydrogen
C. Sodium and potassium
D. Hydrogen and potassium
Correct Answer: D. Hydrogen and potassium
In upper gastrointestinal fluid loss, hydrogen and potassium are lost because these electrolytes are present in abundance in the stomach. The vomiting of gastric or intestinal contents most commonly involves the loss of fluid that contains chloride, potassium, sodium, and bicarbonate. The sequelae of these losses include dehydration along with hyponatremia, hypochloremia, and hypokalemia.
Option A: Low serum magnesium can be commonly associated with hypocalcemia due to induced PTH resistance. It is uncommon above a serum magnesium level of 1mg/dL. Severe hypermagnesemia, although rare, can also cause hypocalcemia by suppressing PTH secretion through a decreased sensitivity of calcium-sensing receptors.
Option B: Physiological stimuli that cause vasopressin release in adjunct with increased fluid intake can cause hyponatremia. Hypothyroidism and adrenal insufficiency may contribute to an increased release of vasopressin. Physiological stimuli for vasopressin release include loss of intravascular volume (hypovolemic hyponatremia) and the loss of effective intravascular volume (hypervolemic hyponatremia).
Option C: The etiology of hyponatremia can be classified based upon the volume status of the extracellular fluid. As mentioned earlier, sodium is the major solute of extracellular fluid (ECF). Based upon the volume of ECF, a patient can be classified into hypovolemic, euvolemic, or hypervolemic.
No comments:
Post a Comment