CNS drugs and antiepileptics: inhalational agent for fast emergence: practice question

A Pharmacology 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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Pharmacology · CNS drugs and antiepileptics: inhalational agent for fast emergence

Sample item

A day-care surgeon wants an inhalational agent with the fastest onset and recovery for a short procedure in a patient already intubated. Which agent has the lowest blood:gas partition coefficient of these?

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

The answer and the reasoning

B. Desflurane

A low blood:gas solubility means the anaesthetic equilibrates quickly between alveoli and brain, giving rapid induction and recovery. Desflurane has the lowest value among the volatile agents listed, though it irritates the airway and so is not used for inhalational induction.

Option by option

  • A. Isoflurane

    Isoflurane is more soluble and gives slower induction and recovery.

  • B. Desflurane (correct)

    Correct. Desflurane has the lowest blood:gas coefficient and so the quickest emergence.

  • C. Sevoflurane

    Sevoflurane is quick and non-irritant but is more soluble than desflurane.

  • D. Halothane

    Halothane has the highest solubility of these, giving the slowest equilibration.

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 Pharmacology questions

Questions about this Pharmacology question

What is the answer to this Pharmacology question?

The best answer is B, Desflurane. A low blood:gas solubility means the anaesthetic equilibrates quickly between alveoli and brain, giving rapid induction and recovery.

Why is "Isoflurane" not the answer?

Isoflurane is more soluble and gives slower induction and recovery.

Why is "Sevoflurane" not the answer?

Sevoflurane is quick and non-irritant but is more soluble than desflurane.

Why is "Halothane" not the answer?

Halothane has the highest solubility of these, giving the slowest equilibration.

What concept does this question test?

It tests CNS drugs and antiepileptics: inhalational agent for fast emergence in Pharmacology. Desflurane has the lowest value among the volatile agents listed, though it irritates the airway and so is not used for inhalational induction.

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 CNS drugs and antiepileptics: inhalational agent for fast emergence?

Learn drugs as classes, then the exception in each class that an examiner would pick. Then use the flashcards and the other Pharmacology 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.