Combined inhaled anticholinergics and beta2-agonists for initial treatment of acute asthma in children.

Several randomized controlled trials have examined, with conflicting results, the efficacy of the addition of anticholinergics to beta2 agonists in acute pediatric asthma. The pooling for a larger number of randomized controlled trials may provide not only greater power for detecting group differences and also provide better insight into the influence of patients' characteristics and treatment modalities on efficacy.