Obstetric anaesthesia: pregnancy physiology: 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 · Obstetric anaesthesia: pregnancy physiology

Sample item

Which respiratory change occurs in term pregnancy and makes hypoxia develop quickly on apnoea?

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

The answer and the reasoning

A. Reduced functional residual capacity with increased oxygen consumption

FRC falls by about 20% while oxygen consumption rises by about 20%, so desaturation occurs within about a minute. Minute ventilation rises by about 50% and MAC falls by about 30%.

Option by option

  • A. Reduced functional residual capacity with increased oxygen consumption (correct)

    Correct. Low FRC and high consumption lead to rapid desaturation.

  • B. Increased FRC

    FRC falls in pregnancy.

  • C. Increased residual volume

    Residual volume falls.

  • D. Reduced minute ventilation

    Minute ventilation increases.

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 A, Reduced functional residual capacity with increased oxygen consumption. FRC falls by about 20% while oxygen consumption rises by about 20%, so desaturation occurs within about a minute.

Why is "Increased FRC" not the answer?

FRC falls in pregnancy.

Why is "Increased residual volume" not the answer?

Residual volume falls.

Why is "Reduced minute ventilation" not the answer?

Minute ventilation increases.

What concept does this question test?

It tests Obstetric anaesthesia: pregnancy physiology in Anaesthesia. Minute ventilation rises by about 50% and MAC falls by about 30%.

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 Obstetric anaesthesia: pregnancy physiology?

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.