A randomized trial of magnesium in the emergency department treatment of children with asthma.

STUDY OBJECTIVE Magnesium sulfate has been shown to benefit asthmatic children and adults with poor responses to initial beta(2)-agonist therapy in the emergency department. We sought to determine whether the routine early administration of high-dose magnesium would benefit moderate to severely ill children with acute asthma. METHODS This was a randomized, double-blind, placebo-controlled trial of 54 children 1 to 18 years of age who presented to the ED of a tertiary care children's hospital with a moderate to severe asthma exacerbation. After receiving a nebulized albuterol treatment (0.15 mg/kg) and methylprednisolone (1 mg/kg), patients were randomly assigned to receive either 75 mg/kg of magnesium sulfate (maximum 2.5 g) or placebo. Thereafter, all patients were treated with frequent nebulized albuterol following a structured protocol. The main outcome was degree of improvement as assessed by Pulmonary Index scores over 120 minutes. Secondary outcomes included hospitalization rates and time required to meet discharge criteria. RESULTS The mean change in Pulmonary Index score from baseline to 120 minutes was 2.83 for the magnesium group compared with 2.66 for the placebo group (95% confidence interval -1. 24 to 1.60). Eleven (46%) of 24 magnesium-treated patients were hospitalized compared with 16 (53%) of 30 in the placebo group (95% confidence interval -19% to 34%). There were no statistically significant differences between the groups with respect to time required to meet discharge criteria. CONCLUSION The routine administration of high-dose magnesium to moderate to severely ill children with asthma, as an adjunct to initial treatment with albuterol and corticosteroids, was not efficacious.