Young asthmatic male in emergency department. RR 26, pCO2 27, SAO2 92%, struggling talking in sentences. Given nebulised salbutamol, and ipratropium, 200mg IV hydrocortisone. After 30 minutes - no improvement. Further management:
A. IV salbutamol
B. IV aminophylline
C. IV magnesium
D. Intubate and ventilate
Answer: C