Insulin for hyperkalaemia — FRCA Primary MCQ

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HardPharmacologyInsulin for hyperkalaemiaFRCA Primary

A patient with renal failure and potassium 6.8 mmol L-1 receives insulin with glucose before induction. What is the most likely explanation?

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Correct answer: E — It stimulates intracellular potassium uptake

Insulin stimulates cellular uptake of potassium, temporarily reducing serum potassium. It directly inhibits activated factor X is less appropriate because it would fit a different clinical clue or a separate anaesthetic problem. It blocks voltage-gated sodium channels is less appropriate because it would fit a different clinical clue or a separate anaesthetic problem. It activates central alpha-2 receptors is less appropriate because it would fit a different clinical clue or a separate anaesthetic problem. It chelates unfractionated heparin is less appropriate because it would fit a different clinical clue or a separate anaesthetic problem. In Primary FRCA pharmacology, link the clinical effect to the receptor, distribution or elimination mechanism rather than memorising isolated facts.

Reference: Peck, Hill & Williams Pharmacology for Anaesthesia and Intensive Care; BNF; Primary FRCA textbooks