Cardiac anaesthesia: heparin for bypass: 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 · Cardiac anaesthesia: heparin for bypass

Sample item

Before initiating cardiopulmonary bypass, heparin is given and anticoagulation is confirmed. Which monitoring test and target are used?

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

The answer and the reasoning

A. Activated clotting time above about 400 to 480 seconds

Full heparinisation, usually 300 to 400 units/kg, is required before bypass, and the activated clotting time is used to confirm it, with a target above about 400 to 480 seconds. After bypass, protamine reverses the heparin effect and the ACT is rechecked. PT and platelet counts do not guide intraoperative heparin dosing.

Option by option

  • A. Activated clotting time above about 400 to 480 seconds (correct)

    Correct. The ACT is the bedside test for heparin effect on bypass.

  • B. Platelet count above 150,000

    A platelet count does not assess heparinisation.

  • C. Prothrombin time of 12 seconds

    The PT does not measure heparin effect.

  • D. Bleeding time under 5 minutes

    Bleeding time is not used to monitor heparin.

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, Activated clotting time above about 400 to 480 seconds. Full heparinisation, usually 300 to 400 units/kg, is required before bypass, and the activated clotting time is used to confirm it, with a target above about 400 to 480 seconds.

Why is "Platelet count above 150,000" not the answer?

A platelet count does not assess heparinisation.

Why is "Prothrombin time of 12 seconds" not the answer?

The PT does not measure heparin effect.

Why is "Bleeding time under 5 minutes" not the answer?

Bleeding time is not used to monitor heparin.

What concept does this question test?

It tests Cardiac anaesthesia: heparin for bypass in Anaesthesia. After bypass, protamine reverses the heparin effect and the ACT is rechecked. PT and platelet counts do not guide intraoperative heparin dosing.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. 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 Cardiac anaesthesia: heparin for bypass?

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.