General anaesthetics: propofol infusion syndrome: 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 · General anaesthetics: propofol infusion syndrome

Sample item

A 25-year-old man with severe head injury has been sedated with a high-dose propofol infusion for four days. He develops metabolic acidosis, rhabdomyolysis, hyperkalaemia, rising triglycerides and bradyarrhythmia. What is the underlying mechanism?

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

The answer and the reasoning

A. Impaired mitochondrial fatty acid oxidation and respiratory chain function

Propofol infusion syndrome occurs after prolonged high-dose infusion, particularly in critically ill patients, and is attributed to impaired mitochondrial fatty acid oxidation and electron transport. Cardiac failure, lactic acidosis, rhabdomyolysis and hypertriglyceridaemia follow. Treatment is to stop propofol and give supportive care; haemofiltration may be required.

Option by option

  • A. Impaired mitochondrial fatty acid oxidation and respiratory chain function (correct)

    Mitochondrial dysfunction blocks fatty acid use, producing acidosis, rhabdomyolysis and arrhythmia.

  • B. Mutation of the ryanodine receptor with uncontrolled calcium release

    A ryanodine receptor defect underlies malignant hyperthermia, triggered by volatile agents and succinylcholine, not propofol.

  • C. Accumulation of an active renal metabolite

    Propofol is metabolised to inactive glucuronides, and no active renal metabolite accumulates.

  • D. Hypersensitivity to egg lecithin in the lipid vehicle

    Lecithin hypersensitivity causes allergic reactions and does not explain this multi-organ picture.

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 Pharmacology question

What is the answer to this Pharmacology question?

The best answer is A, Impaired mitochondrial fatty acid oxidation and respiratory chain function. Propofol infusion syndrome occurs after prolonged high-dose infusion, particularly in critically ill patients, and is attributed to impaired mitochondrial fatty acid oxidation and electron transport.

Why is "Mutation of the ryanodine receptor with uncontrolled calcium release" not the answer?

A ryanodine receptor defect underlies malignant hyperthermia, triggered by volatile agents and succinylcholine, not propofol.

Why is "Accumulation of an active renal metabolite" not the answer?

Propofol is metabolised to inactive glucuronides, and no active renal metabolite accumulates.

Why is "Hypersensitivity to egg lecithin in the lipid vehicle" not the answer?

Lecithin hypersensitivity causes allergic reactions and does not explain this multi-organ picture.

What concept does this question test?

It tests General anaesthetics: propofol infusion syndrome in Pharmacology. Cardiac failure, lactic acidosis, rhabdomyolysis and hypertriglyceridaemia follow. Treatment is to stop propofol and give supportive care; haemofiltration may be required.

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 General anaesthetics: propofol infusion syndrome?

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.