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Life-threatening acute asthma — SCE Acute Medicine MCQ

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ModerateAcute Respiratory PresentationsLife-threatening acute asthmaSCE Acute Medicine

A 29-year-old man with asthma is brought to the acute medical unit after using his salbutamol inhaler repeatedly overnight. He can speak in short phrases, RR 34, HR 124, PEF 180 L/min from a best of 620 L/min, and SpO2 is 93% on air. After oxygen, back-to-back nebulised salbutamol and ipratropium, and oral prednisolone, his PEF remains 190 L/min and he is exhausted. What is the most appropriate next step in management?

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Correct answer: A — Give intravenous magnesium sulphate

The patient has life-threatening features and a poor response to initial bronchodilator therapy, making IV magnesium sulphate an appropriate escalation. Discharge and routine spirometry are unsafe because the attack remains severe. Oral theophylline is slower and less favoured than magnesium in this context. A useful examination point is that a falling or static PEF after initial treatment carries more weight than a reassuring single oxygen saturation.

Reference: BTS/SIGN/NICE asthma guideline, BNF