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Nitrous oxide after intraocular gas surgery — FRCA Primary MCQ

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HardPharmacologyNitrous oxide after intraocular gas surgeryFRCA Primary

A patient has a residual intraocular gas bubble after retinal surgery and requires general anaesthesia. Which gas is contraindicated?

Educational content. Not a substitute for clinical judgement or local policy.

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Correct answer: CNitrous oxide

The best answer is “Nitrous oxide”. Nitrous oxide enters closed gas spaces more rapidly than nitrogen can leave them and can expand a residual intraocular gas bubble. This can cause a dangerous rise in intraocular pressure and irreversible visual loss. The other inhaled anaesthetic agents listed do not have this closed-space expansion effect.

Reference: South Tees Hospitals NHS Foundation Trust, Gas in your eye: https://www.southtees.nhs.uk/resources/gas-in-your-eye/