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Entonox contraindication in pneumothorax — DipIMC MCQ

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ModeratePre-hospital PharmacologyEntonox contraindication in pneumothoraxDipIMC

A 24-year-old rugby player has a suspected pneumothorax after chest trauma and severe pain. A colleague suggests Entonox during packaging. What is the most appropriate immediate action?

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

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Correct answer: C — Avoid Entonox and use an alternative analgesic strategy

Nitrous oxide diffuses into closed gas spaces and is avoided in suspected pneumothorax. Alternative analgesia, such as titrated opioid or ketamine depending on scope and physiology, should be considered. Delaying analgesia is poor care and can worsen ventilation. The pearl is that analgesic contraindications matter in trauma, especially chest injury and decompression illness.

Reference: JRCALC Guidelines 2025; ATACC