Bronchiolitis is a winter disease that occurs in children younger than two years. It usually is associated with respiratory syncytial virus infection and results in respiratory difficulty, wheezing, and chest crackles on auscultation. The diagnosis often is made in children who have not had a history of wheezing, but it is difficult to distinguish this condition from asthma. Because there is no curative treatment, bronchodilators have been used to treat symptoms of bronchiolitis. In an abstract of a Cochrane systematic review, with commentary by Turner and Evered, randomized studies evaluating bronchodilator therapy for bronchiolitis were reviewed.

To be included in the review, studies had to have a placebo-controlled design with outcomes related to symptoms and signs. Some of the 20 studies included had the following limitations: (1) variation among the subjects, with some of them having recurrent wheezes, and (2) failure to identify the clinical significance of symptom score improvements.

Use of bronchodilators did not improve oxygenation or change the rate or duration of hospitalization. Patients treated with bronchodilators had significantly more adverse events, including tachycardia, increased blood pressure, decreased oxygen saturation, flushing, hyperactivity, prolonged cough, and tremor.

The Cochrane systematic review authors conclude that bronchodilator use in children with bronchiolitis offers a modest, short-term improvement in clinical scores when symptoms are mild to moderately severe. Because of high cost and uncertain benefit, routine use of this therapy cannot be recommended.

Turner and Evered note that bronchodilators commonly are used with oxygen and intravenous fluids in children hospitalized with bronchiolitis. The minor symptomatic relief offered by this treatment may not be worth the cost and the potential for adverse events. Routine use of bronchodilators probably is not appropriate. Further research to determine which children with bronchiolitis would benefit from bronchodilator therapy and what other therapies might be useful is needed.