Purpose: To determine whether inhaled ipratropium bromide provides an additive, clinically important improvement in children with acute asthma who are being treated with beta 2-agonists.
Methods: An English-language literature search was conducted employing MEDLINE (1966 to 1992), Science Citation Index (1986 to 1992) using key citations, bibliographic reviews of primary research and review articles, and correspondence with authors of recent articles. After independent review by two observers, six studies were selected on the basis of prespecified selection criteria. Two observers independently assessed the selected papers by using explicit methodologic criteria for evaluating the quality of studies dealing with therapeutic intervention.
Results: None of the six studies found a significant difference in clinical rating score, admission rate, or length of stay in hospital between the ipratropium bromide and the control groups. The three studies with the highest methodologic validity measured the change in percentage predicted forced expiratory volume in 1 second (FEV1) from baseline to 60 minutes. The pooled effect size (95% CI) for these studies was 0.88 (0.42-1.34), which translates to an improvement in percentage predicted FEV1 over the control group of 12.5% (95% CI, 6.6-18.4). In a subset of 23 children who had severe airway obstruction, peak expiratory flow rate (PEFR) responded better to a beta 2-agonist alone (p = 0.007).
Conclusion: The existing evidence reveals that the addition of ipratropium bromide to a beta 2-agonist offers a statistically significant improvement in percentage predicted FEV1 but no clinical improvement. As it may cause deterioration in PEFR in severely asthmatic children, ipratropium bromide should not be used universally for acute childhood asthma until further research determines the clinical significance of these spirometric changes.