Postpartum haemorrhage and emergencies: oxytocin bolus effect: practice question

A OBG 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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OBG · Postpartum haemorrhage and emergencies: oxytocin bolus effect

Sample item

At caesarean section the anaesthetist pushes 10 IU of oxytocin as a rapid intravenous bolus. Which haemodynamic effect is most likely?

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

The answer and the reasoning

A. Vasodilatation with hypotension and reflex tachycardia

Oxytocin relaxes vascular smooth muscle when given as a fast bolus, so blood pressure drops and heart rate rises. It is therefore given as a slow infusion or diluted slow injection at caesarean, especially in hypovolaemic or cardiac patients.

Option by option

  • A. Vasodilatation with hypotension and reflex tachycardia (correct)

    Correct. A rapid bolus causes vasodilatation, hypotension and compensatory tachycardia.

  • B. Bronchospasm with a rise in pulmonary pressure

    Bronchospasm is a recognised effect of carboprost, not oxytocin.

  • C. Hypertension with reflex bradycardia

    Hypertension with bradycardia is the pressor response seen with ergometrine.

  • D. Sustained hypertension with peripheral vasoconstriction

    Vasoconstriction with hypertension is the picture of ergot alkaloids, not oxytocin.

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 OBG questions

Questions about this OBG question

What is the answer to this OBG question?

The best answer is A, Vasodilatation with hypotension and reflex tachycardia. Oxytocin relaxes vascular smooth muscle when given as a fast bolus, so blood pressure drops and heart rate rises.

Why is "Bronchospasm with a rise in pulmonary pressure" not the answer?

Bronchospasm is a recognised effect of carboprost, not oxytocin.

Why is "Hypertension with reflex bradycardia" not the answer?

Hypertension with bradycardia is the pressor response seen with ergometrine.

Why is "Sustained hypertension with peripheral vasoconstriction" not the answer?

Vasoconstriction with hypertension is the picture of ergot alkaloids, not oxytocin.

What concept does this question test?

It tests Postpartum haemorrhage and emergencies: oxytocin bolus effect in OBG. It is therefore given as a slow infusion or diluted slow injection at caesarean, especially in hypovolaemic or cardiac patients.

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 Postpartum haemorrhage and emergencies: oxytocin bolus effect?

Learn management algorithms as steps: PPH, eclampsia, ectopic pregnancy. Then use the flashcards and the other OBG 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.