Regional anaesthesia: 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 · Regional anaesthesia

Sample item

Ten minutes after a spinal block for caesarean section, a woman feels nauseated and her blood pressure falls markedly. What is the main mechanism of the hypotension?

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

The answer and the reasoning

D. Preganglionic sympathetic blockade causing vasodilatation and reduced venous return

Spinal anaesthesia blocks sympathetic outflow, producing arterial and venous dilatation and venous pooling. Aortocaval compression by the gravid uterus worsens this. Left uterine displacement, fluids and a vasopressor such as phenylephrine or ephedrine are used.

Option by option

  • A. Anaphylaxis to the local anaesthetic

    Anaphylaxis is rare and would usually bring bronchospasm, rash or oedema.

  • B. Hypovolaemia from concealed haemorrhage

    Nothing in the history suggests concealed bleeding, and the timing relates to the block.

  • C. Direct negative inotropic effect of the intrathecal drug on the myocardium

    The small intrathecal dose has no significant direct myocardial depressant effect.

  • D. Preganglionic sympathetic blockade causing vasodilatation and reduced venous return (correct)

    Correct. Sympathetic block with venous pooling is the usual cause.

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 Anaesthesia questions

Questions about this Anaesthesia question

What is the answer to this Anaesthesia question?

The best answer is D, Preganglionic sympathetic blockade causing vasodilatation and reduced venous return. Spinal anaesthesia blocks sympathetic outflow, producing arterial and venous dilatation and venous pooling.

Why is "Anaphylaxis to the local anaesthetic" not the answer?

Anaphylaxis is rare and would usually bring bronchospasm, rash or oedema.

Why is "Hypovolaemia from concealed haemorrhage" not the answer?

Nothing in the history suggests concealed bleeding, and the timing relates to the block.

Why is "Direct negative inotropic effect of the intrathecal drug on the myoca…" not the answer?

The small intrathecal dose has no significant direct myocardial depressant effect.

What concept does this question test?

It tests Regional anaesthesia in Anaesthesia. Aortocaval compression by the gravid uterus worsens this. Left uterine displacement, fluids and a vasopressor such as phenylephrine or ephedrine are used.

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 Regional anaesthesia?

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.