Paediatric surgery: pyloric stenosis: practice question

A General Surgery 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.

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General Surgery · Paediatric surgery: pyloric stenosis

Sample item

A 4-week-old infant has non-bilious projectile vomiting and an olive-shaped epigastric mass. Which metabolic disturbance is expected?

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

The answer and the reasoning

D. Hypochloraemic hypokalaemic metabolic alkalosis

Loss of gastric hydrochloric acid through persistent vomiting produces hypochloraemic metabolic alkalosis; volume depletion drives renal potassium loss.

Option by option

  • A. High-anion-gap metabolic acidosis

    No organic acid accumulation is implied.

  • B. Respiratory acidosis

    The primary disturbance is metabolic, not respiratory.

  • C. Hyperkalaemic acidosis

    Potassium is typically depleted, not elevated.

  • D. Hypochloraemic hypokalaemic metabolic alkalosis (correct)

    Correct. Gastric acid and potassium loss create this characteristic pattern.

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.

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Questions about this General Surgery question

What is the answer to this General Surgery question?

The best answer is D, Hypochloraemic hypokalaemic metabolic alkalosis. Loss of gastric hydrochloric acid through persistent vomiting produces hypochloraemic metabolic alkalosis; volume depletion drives renal potassium loss.

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

No organic acid accumulation is implied.

Why is "Respiratory acidosis" not the answer?

The primary disturbance is metabolic, not respiratory.

Why is "Hyperkalaemic acidosis" not the answer?

Potassium is typically depleted, not elevated.

What concept does this question test?

It tests Paediatric surgery: pyloric stenosis in General Surgery. The correct option holds because: Correct. Gastric acid and potassium loss create this characteristic pattern.

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 Paediatric surgery: pyloric stenosis?

Learn classic signs and eponyms alongside what they diagnose. Then use the flashcards and the other General Surgery 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.