Neuromuscular blockade: succinylcholine: 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 · Neuromuscular blockade: succinylcholine

Sample item

A patient with a major crush injury sustained three weeks ago requires emergency intubation. Which reason makes succinylcholine potentially dangerous in this setting?

AIt reliably causes severe hypoglycemiaBIt causes irreversible renal failureCRisk of exaggerated hyperkalemia from upregulated acetylcholine receptorsDIt prevents fasciculations in all patients

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

The answer and the reasoning

C. Risk of exaggerated hyperkalemia from upregulated acetylcholine receptors

After denervation, burns, crush injury, and some neuromuscular conditions, extrajunctional acetylcholine receptors may be upregulated. Succinylcholine can then cause a dangerous potassium release and arrhythmia.

Option by option

A. It reliably causes severe hypoglycemia
Hypoglycemia is not a defining succinylcholine hazard.
B. It causes irreversible renal failure
Renal failure is not its characteristic direct acute toxicity.
C. Risk of exaggerated hyperkalemia from upregulated acetylcholine receptors (correct)
Correct. Receptor upregulation can produce life-threatening hyperkalemia after depolarization.
D. It prevents fasciculations in all patients
Succinylcholine commonly causes fasciculations before paralysis.

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.

Questions about this Anaesthesia question

What is the answer to this Anaesthesia question?

The best answer is C, Risk of exaggerated hyperkalemia from upregulated acetylcholine receptors. After denervation, burns, crush injury, and some neuromuscular conditions, extrajunctional acetylcholine receptors may be upregulated.

Why is "It reliably causes severe hypoglycemia" not the answer?

Hypoglycemia is not a defining succinylcholine hazard.

Why is "It causes irreversible renal failure" not the answer?

Renal failure is not its characteristic direct acute toxicity.

Why is "It prevents fasciculations in all patients" not the answer?

Succinylcholine commonly causes fasciculations before paralysis.

What concept does this question test?

It tests Neuromuscular blockade: succinylcholine in Anaesthesia. Succinylcholine can then cause a dangerous potassium release and arrhythmia.

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 Neuromuscular blockade: succinylcholine?

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.