Usefulness of inhaled magnesium sulfate in the coadjuvant management of severe asthma crisis in an emergency department

Abstract Rationale Treatment of severe asthma may be difficult despite the use of several medications including parenteral corticosteroids. Intravenous magnesium sulfate (MgSO4 ) is one ancillary drug for severe crisis; its inhaled use is controversial. Objectives To evaluate the usefulness of inhaled MgSO4 compared to placebo in improving lung function, oxygen saturation, and reducing hospital admission as an adjunct to standard treatment in severe asthma crisis. Patients and methods We conducted a placebo-controlled, double-blind clinical trial with asthmatic patients >18 years of age with asthmatic crisis and FEV1 < 60% of predicted (%p). All subjects received 125 mg of IV methylprednisolone followed by nebulization with the combination of albuterol (7.5 mg) and ipratropium bromide (1.5 mg) diluted in 3 ml of isotonic saline solution (as placebo) or 3 ml (333 mg) of MgSO4 . After 90 min, subjects with FEV1 < 60%p or SpO2 < 88% or persistent symptoms were admitted to the emergency department (ED). Results We included 30 patients per group who were similar at baseline. The MgSO4 group showed higher post-bronchodilator (post-BD) FEV1 %p (69 ± 13 vs. 61 ± 12, p < 0.014) and SpO2 (92 ± 4 vs. 88 ± 5%, p < 0.006) than the placebo group. Fewer treated patients were admitted to the ED (5 vs. 13) ( p < 0.047), with relative risk (RR) of 0.26 (95% CI 0.079–0.870). Conclusions Adding inhaled MgSO4 treatment to standard therapy in severe asthma crisis improves FEV1 %p and SpO2 post-BD and reduces the rate of ED admissions.