Question

What is the metabolic finding seen in a baby with CHPS?

• A. Hyperchloremic hypernatremic metabolic alkalosis
• B. Hypochloremic hypernatremic metabolic acidosis
• C. Hypochloremic hyponatremic metabolic alkalosis
• D. Hyperchloremic hyponatremic metabolic alkalosis

Answer 1

The Correct Option is C

The condition in discussion is Congenital Hypertrophic Pyloric Stenosis (CHPS), which is a condition that causes projectile vomiting in infants due to the narrowing of the pylorus. The vomiting leads to loss of gastric acid, which contains hydrochloric acid (HCl). This results in several characteristic metabolic findings in the baby:

1. Hypochloremia: Loss of hydrochloric acid from persistent vomiting leads to a decrease in chloride ions (Cl-).
2. Hyponatremia: Although initial sodium levels might be normal or elevated due to dehydration, continued vomiting and subsequent rehydration without electrolytes often result in low sodium levels.
3. Metabolic Alkalosis: The loss of acidic gastric contents causes an increase in blood pH, leading to alkalosis. The kidneys attempt to compensate by excreting bicarbonate, but this compensation is often incomplete or delayed.

Therefore, the metabolic finding in CHPS is characterized by hypochloremic hyponatremic metabolic alkalosis.