A 24-year-old woman with acute severe asthma presents to the emergency department with silent chest, SpO2 84% on room air, and altered sensorium. Initial nebulized salbutamol and ipratropium have failed. Which is the most appropriate immediate next step?
- A Intravenous aminophylline infusion
- B Nebulized adrenaline (epinephrine)
- C Intravenous magnesium sulfate ✓
- D Subcutaneous terbutaline
Correct answer: C. Intravenous magnesium sulfate
Explanation
In life-threatening asthma with poor response to initial bronchodilators, intravenous magnesium sulfate (2 g IV over 20 minutes) is recommended by BTS/SIGN and GINA guidelines as the next step before considering intubation. It acts as a smooth muscle relaxant. Aminophylline is no longer recommended due to narrow therapeutic index and lack of additional benefit over beta-agonists plus IV steroids.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.