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Entonox contraindications — DIPIMC MCQ

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HardPharmacology (Pre-Hospital)Entonox contraindicationsDIPIMCDipIMC

A cooperative patient requests Entonox after trauma. Which finding would make nitrous-oxide analgesia unsuitable?

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

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Correct answer: D — A suspected pneumothorax after blunt chest trauma

The best answer is “A suspected pneumothorax after blunt chest trauma”. Nitrous oxide diffuses into closed gas spaces faster than nitrogen leaves them, so it can expand a pneumothorax and worsen respiratory compromise. It is also unsuitable with other trapped-gas conditions such as bowel obstruction or decompression illness and requires a conscious, cooperative patient able to self-administer. The other injuries do not by themselves create a closed gas-space contraindication.

Reference: University Hospitals Sussex, Entonox: https://www.uhsussex.nhs.uk/resources/entonox/