Equipment: vaporisers: 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 · Equipment: vaporisers

Sample item

A modern agent-specific vaporiser delivers a constant output across fluctuating flows and temperatures. Which design features account for this?

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

The answer and the reasoning

B. Variable bypass with temperature compensation, out of circuit

Tec-type vaporisers split flow between a bypass channel and a vaporising chamber and use bimetallic strips or expansion elements to adjust the split with temperature. They sit outside the breathing circuit.

Option by option

  • A. Pressure-compensated needle valve only

    A needle valve alone does not provide compensation.

  • B. Variable bypass with temperature compensation, out of circuit (correct)

    Correct. Variable bypass with temperature compensation.

  • C. Heated chamber for all agents

    Only desflurane needs a heated chamber.

  • D. Draw-over design with no bypass

    Draw-over vaporisers are different and used in the field.

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 B, Variable bypass with temperature compensation, out of circuit. Tec-type vaporisers split flow between a bypass channel and a vaporising chamber and use bimetallic strips or expansion elements to adjust the split with temperature.

Why is "Pressure-compensated needle valve only" not the answer?

A needle valve alone does not provide compensation.

Why is "Heated chamber for all agents" not the answer?

Only desflurane needs a heated chamber.

Why is "Draw-over design with no bypass" not the answer?

Draw-over vaporisers are different and used in the field.

What concept does this question test?

It tests Equipment: vaporisers in Anaesthesia. They sit outside the breathing circuit.

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 Equipment: vaporisers?

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.