Q: High output via nasogastric suction tubes in ICU patients may result in severe hypokalemia and which acid-base disorder?
A) Metabolic acidosis
B) Respiratory acidosis
C) Metabolic alkalosis
D) Respiratory alkalosis
E) Triple acid base disorder
Severe hypokalemia results in metabolic alkalosis due to an intracellular shift or loss of hydrogen ion. This is chloride-responsive metabolic alkalosis, means it can be suspected if urine chloride is < 10 mEq/L.
In ICU, high output via nasogastric suction tubes is the most common cause of severe hypokalemia due to loss of hydrochloric acid (H+ and Cl-). Concomitant hyponatremia leads kidney to compensate by retaining sodium in the collecting ducts at the expense of hydrogen ions.
Hennessey, Iain. Japp, Alan.Arterial Blood Gases Made Easy. Churchill Livingstone 1 edition (18 Sep 2007).