A Meta-analysis on Intravenous Magnesium Sulphate for Treating Acute Asthma

Purpose of the Study. To evaluate the effectiveness of intravenous magnesium sulfate in the treatment of acute asthmatic attacks in children. Study Population. Pediatric patients (n = 182) with moderate-to-severe asthmatic attacks in the emergency department in 5 randomized, placebo-controlled trials comparing intravenous magnesium sulfate to placebo, with co-therapies of inhaled β2 agonists and systemic steroids. Methods. Meta-analysis that evaluated outcomes of hospitalization, short-term pulmonary-function tests, and symptom scores. Results. Magnesium sulfate was effective in preventing hospitalization (odds ratio: 0.29; 95% confidence interval: 0.143–0.589). The number needed to treat was 4 (95% confidence interval: 3–8). Secondary outcomes of short-term pulmonary-function tests and clinical symptom scores also showed significant improvement. The therapy was well tolerated with only minor adverse effects reported. Conclusion. Intravenous magnesium sulfate probably provides additional benefit in moderate-to-severe acute asthma in children treated with bronchodilators and steroids. Reviewer Comments. Meta-analyses are useful when multiple previous studies have shown inconsistent results. They may not, however, be the final answer, because subsequent large trials can alter the conclusion of a meta-analysis. Nonetheless, the data to date considered in this meta-analysis seem quite convincing. Also, the treatment is inexpensive and well tolerated, and the number needed to treat is small (you would need to give this therapy to only 4 children to keep 1 out of the hospital).