To determine if intravenous magnesium, useful for severe pediatric asthma, reduces time to medical readiness for discharge in bronchiolitis patients when added to supportive care
We compared a single dose of 100 mg/kg intravenous magnesium sulfate versus placebo for acute bronchiolitis. Patients received bronchodilator therapy, nebulized hypertonic saline, and 5 days of dexamethasone if there was eczema and/or a family history of asthma. Time to medical readiness for discharge was the primary efficacy outcome. Bronchiolitis severity scores and need for infirmary or hospital admission and for clinic revisits within 2 wk were secondary outcomes. Cardiorespiratory instability onset was the safety outcome.
162 previously healthy infants diagnosed with bronchiolitis aged 22 days to 17.6 months, median 3.7 months, were enrolled. About half had eczema and/or a family history of asthma. 86.4% had positive nasopharyngeal virus swabs. Geometric mean time until medical readiness for discharge was 24.1h (95% CI, 20.0-29.1) for the 78 magnesium patients and 25.3h (95% CI, 20.3-31.5) for the 82 placebo patients (ratio 0.95; 95% CI,0.52-1.80, p=0.91). Mean bronchiolitis severity scores over time were similar for the two groups. The frequency of clinic visits in the subsequent 2 wk, 33.8% and 27.2%, respectively, was also similar. Fifteen (19.5%) magnesium versus 5 (6.2%) placebo patients were readmitted to infirmary or hospital within 2 wk (p= 0.016). No acute cardiorespiratory side effects were reported.
Intravenous magnesium did not provide benefit for patients with acute bronchiolitis and may be harmful.