Intravenous magnesium sulfate for acute wheezing in young children: a randomised double-blind trial

Magnesium sulfate has been shown to be an effective treatment in older children with asthma exacerbations, but it has not been investigated in acute severe virus-induced wheezing in young children. The study enrolled 61 children aged 6 months to 4 years. Inclusion criteria were severe wheezing, classified as a score of >= 6 points as assessed by the Respiratory Distress Assessment Instrument (RDAI) after initial treatment with salbutamol, and the symptoms of acute viral infection. The children were randomly allocated to receive either an infusion of magnesium sulfate (40 mg.kg(-1)) or 0.9% sodium chloride as a placebo infusion for 20 min. Primary outcome measure was mean change in RDAI scores from baseline to 6 h after the treatment. Change in the severity of wheezing from baseline to 6 h after the treatment, as measured by mean +/- SD RDAI scores, was 4.7 +/- 2.6 in the magnesium sulfate group and 4.2 +/- 4.2 in the placebo group (difference 0.5, 95% CI -1.3 to 2.3, p=0.594). Intravenous magnesium sulfate was ineffective in treating acute severe virus-induced wheezing in young children, in contrast to the previous efficacy demonstrated in older children.