Gastroenterology: pyloric stenosis: practice question

A Pediatrics question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

Try it

Pediatrics · Gastroenterology: pyloric stenosis

Sample item

A 5-week-old has progressive nonbilious projectile vomiting after feeds, remains hungry, and has a palpable epigastric olive. Which electrolyte disturbance is expected?

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

A. Hypochloremic hypokalemic metabolic alkalosis

Persistent vomiting of gastric hydrochloric acid in hypertrophic pyloric stenosis produces hypochloremic metabolic alkalosis and often potassium depletion. Fluid and electrolyte correction is required before pyloromyotomy.

Option by option

  • A. Hypochloremic hypokalemic metabolic alkalosis (correct)

    Correct. Loss of gastric acid produces this classic alkalosis.

  • B. High-anion-gap metabolic acidosis

    Acidosis is not the usual consequence of vomiting gastric contents.

  • C. Hyperkalemic acidosis

    Hyperkalemia is not the expected electrolyte change.

  • D. Respiratory alkalosis

    The primary disturbance is metabolic, not respiratory.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

More Pediatrics questions

Questions about this Pediatrics question

What is the answer to this Pediatrics question?

The best answer is A, Hypochloremic hypokalemic metabolic alkalosis. Persistent vomiting of gastric hydrochloric acid in hypertrophic pyloric stenosis produces hypochloremic metabolic alkalosis and often potassium depletion.

Why is "High-anion-gap metabolic acidosis" not the answer?

Acidosis is not the usual consequence of vomiting gastric contents.

Why is "Hyperkalemic acidosis" not the answer?

Hyperkalemia is not the expected electrolyte change.

Why is "Respiratory alkalosis" not the answer?

The primary disturbance is metabolic, not respiratory.

What concept does this question test?

It tests Gastroenterology: pyloric stenosis in Pediatrics. Fluid and electrolyte correction is required before pyloromyotomy.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Gastroenterology: pyloric stenosis?

Memorise milestones and the vaccine schedule as tables and revise them often. Then use the flashcards and the other Pediatrics questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.