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Root cause analysis — USMLE Step 2 CK MCQ

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HardEthics, patient safety, quality improvementRoot cause analysisUSMLE Step 2 CK

A 31-year-old with severe asthma has persistent dyspnea after repeated inhaled albuterol-ipratropium and systemic glucocorticoids. Peak flow is 28% predicted, respiratory rate is 32/min, oxygen saturation is 94% on supplemental oxygen and there is no hypercapnia or exhaustion. Which adjunct is most appropriate now?

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Correct answer: D — Give a single intravenous magnesium sulfate infusion

A single intravenous magnesium sulfate infusion is a reasonable adjunct for a severe asthma exacerbation that remains markedly obstructed after repeated inhaled bronchodilators and systemic glucocorticoids. Aminophylline adds toxicity without routine benefit. Intramuscular epinephrine is used for anaphylaxis or when inhaled therapy cannot be delivered, not as the next standard bronchodilator here. Heliox has no established routine outcome benefit, and ketamine is generally an induction or rescue adjunct when ventilatory support is required rather than treatment for a patient without exhaustion or hypercapnia.

Reference: GINA 2026 strategy report for asthma management and prevention: https://ginasthma.org/2026-gina-strategy-report/