Efficacy of bronchodilator therapy in bronchiolitis - A meta-analysis

Objective: To determine if bronchodilators are efficacious in treating bronchiolitis. Data Sources: A search of bibliographic databases (MEDLINE, Excerpta Medica, and Reference Update) for bronchiolitis and albuterol or ipratropium bromide, or adrenergic agents or bronchodilator agents. Reference lists were also used. Study Selection: Randomized, placebo-controlled trials of bronchodilator treatment in bronchiolitis were selected by 2 investigators. Fifteen of 89 identified publications met the selection criteria. Data Extraction: Investigators independently abstracted data for 3 outcomes: clinical score, oxygen saturation, and hospitalization. Clinical score was measured as a dichotomous variable (score+/-improved) or continuous variable (average score). Data Synthesis: For primary analysis, data were pooled from 8 trials of children with first-time wheezing. The effect size for average score was -0.32 (95% confidence interval [CI], -0.54 to -0.11; P<.01), favoring treatment; the relative risk for score+/-improved was 0.76 (95% CI, 0.60 to 0.95; P=.02), favoring treatment. Bronchodilators had no effect on hospitalization (relative risk, 0.85; 95% CI, 0.47 to 1.53; P=.58), but co-interventions may have been administered prior to this outcome. The results for oxygen saturation were too varied to allow pooling of the results. Secondary analyses were performed on 4 outpatient trials of children with first-time wheezing, 7 trials in which only nebulized beta-agonists were used, and on all 15 trials identified. The results were similar, but the data varied more. Conclusion: Bronchodilators produce modest shortterm improvement in clinical features of mild or moderately severe bronchiolitis.