Complications and emergencies: negative-pressure pulmonary oedema: practice question

A Anaesthesia 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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Anaesthesia · Complications and emergencies: negative-pressure pulmonary oedema

Sample item

A muscular 22-year-old has laryngospasm at the end of a knee arthroscopy and makes forceful inspiratory efforts against a closed glottis. Once the spasm breaks, he coughs up pink frothy sputum and his SpO2 falls to 86 percent, with bilateral crackles. What is the most likely diagnosis?

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

The answer and the reasoning

C. Negative-pressure pulmonary oedema

Strong inspiratory effort against an obstructed airway generates a large negative intrathoracic pressure, which increases venous return and transudation of fluid into the alveoli. It is classically seen in young, muscular patients after laryngospasm and presents within minutes with frothy sputum and hypoxaemia.

Option by option

  • A. Aspiration pneumonitis from gastric acid

    Aspiration would need a history of regurgitation or vomiting and does not produce pink frothy sputum immediately after relief of laryngospasm.

  • B. Tension pneumothorax from barotrauma

    Tension pneumothorax gives unilateral absent breath sounds and hypotension rather than bilateral crackles with frothy sputum.

  • C. Negative-pressure pulmonary oedema (correct)

    Correct. Forceful inspiration against a closed glottis draws fluid into the alveoli, giving acute non-cardiogenic oedema after the obstruction is relieved.

  • D. Cardiogenic oedema from acute left ventricular failure

    A healthy young man with no cardiac history has no reason for left ventricular failure, and the trigger here is airway obstruction.

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 Anaesthesia question

What is the answer to this Anaesthesia question?

The best answer is C, Negative-pressure pulmonary oedema. Strong inspiratory effort against an obstructed airway generates a large negative intrathoracic pressure, which increases venous return and transudation of fluid into the alveoli.

Why is "Aspiration pneumonitis from gastric acid" not the answer?

Aspiration would need a history of regurgitation or vomiting and does not produce pink frothy sputum immediately after relief of laryngospasm.

Why is "Tension pneumothorax from barotrauma" not the answer?

Tension pneumothorax gives unilateral absent breath sounds and hypotension rather than bilateral crackles with frothy sputum.

Why is "Cardiogenic oedema from acute left ventricular failure" not the answer?

A healthy young man with no cardiac history has no reason for left ventricular failure, and the trigger here is airway obstruction.

What concept does this question test?

It tests Complications and emergencies: negative-pressure pulmonary oedema in Anaesthesia. It is classically seen in young, muscular patients after laryngospasm and presents within minutes with frothy sputum and hypoxaemia.

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 Complications and emergencies: negative-pressure pulmonary oedema?

Make a table of each agent, its key advantage and its main side effect. Then use the flashcards and the other Anaesthesia 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.