skip to main content

Entonox contraindication pneumothorax — DipIMC MCQ

Instant feedback + full explanation. One question, done properly.

ModeratePharmacology in Pre-Hospital SettingEntonox contraindication pneumothoraxDipIMC

A 31-year-old man is stabbed in the chest outside a nightclub and is sitting forward with pleuritic pain. He is alert, oxygen saturation is 93% on air and breath sounds are reduced on the injured side. A crew member suggests Entonox while awaiting an enhanced-care team. What is the most appropriate immediate action?

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

Reveal the answer and explanation

Correct answer: A — Avoid Entonox and use alternative analgesia with oxygen if needed

Option A is correct because Nitrous oxide can expand trapped gas spaces and is inappropriate when pneumothorax is suspected. The tempting option is to give Entonox because the patient is in pain and conscious, but this may worsen intrathoracic gas expansion. Analgesia should be provided by safer alternatives while monitoring for tension physiology. Option B is less appropriate because oxygen may be supportive, but it does not address the defining time-critical problem first; option D is less appropriate because vascular access is useful, but it should not delay the immediate priority. Option E is less appropriate because it is plausible in a different scenario but suboptimal for the features described; option C is less appropriate because delay would increase clinical risk. Clinical pearl: in DipIMC-style questions, the best answer is the intervention that changes outcome earliest in the pre-hospital phase.

Reference: JRCALC Guidelines; ATACC