Which of the following metabolic derangements is most likely in a patient with severe, protracted vomiting?
- Hypochloremic, hypokalemic, metabolic alkalosis
- Hypochloremic, hypokalemic, metabolic acidosis
- Hyperchloremic, hypokalemic, metabolic alkalosis
- Hyperchloremic, hypokalemic, metabolic acidosis
- Hyperchloremic, hyperkalemic, metabolic acidosis
Answer: Hypochloremic, hypokalemic, metabolic alkalosis.
Severe, protracted vomiting can cause a hypochloremic, hypokalemic, metabolic alkalosis. The metabolic alkalosis is produced by loss of hydrogen ions in the vomitus. Many factors
serve to maintain the alkalosis including volume contractions,
hypokalemia, chloride depletion, shift of extracellular hydrogen
ions into cells, and increased aldosterone. Hypokalemia is produced primarily by loss of potassium in the urine.
The metabolic alkalosis leads to large amounts of sodium bicarbonate being delivered to the distal tubule. Secondary hyperaldosteronism from volume depletion causes reabsorption of sodium and excretion of large amounts of potassium in the urine.
Hyperchloraemic,Hypokalaemic Metabolic Alkalosis is seen in RTA,Diarrhoea,Acetazolamide & Ureterosigmoid fistulae.