Study objective: The use of nebulized ipratropium in combination with beta-agonists for the treatment of acute asthma in adults is controversial. We wished to test the hypothesis that combined aerosol treatment results in a greater rate of airflow improvement and a lower proportion of hospital admission in adults with acute asthma.
Methods: In a randomized, double-blind, placebo-controlled trial, 55 adult asthmatic patients with peak expiratory flow rate (PEFR) less than 200 L/min were randomly assigned to nebulization treatment with albuterol alone (2.5 mg initial dose followed by 2 more doses at 20-min intervals.), or the same albuterol regimen plus ipratropium (.5 mg combined with the initial dose of albuterol only). Patients were recruited from an emergency department at an urban academic medical center. The primary endpoints were changes in PEFR and in percent predicted PEFR over time (ie, treatment by time effect). PEFRs were assessed at baseline and at 20-minute intervals for a 1-hour period. The proportion of admissions in the two groups were examined as secondary endpoints.
Results: The increases in PEFR and percent predicted PEFR over time were both significantly greater in the combined ipratropium plus albuterol treatment group (P < or = .001). In addition, the proportion admitted patients was less in this group (3/27) than the proportion in the albuterol-only group (10/28). The 95% confidence interval for the absolute difference of 25% in the proportion admitted was 3% to 46%, P = .03. Most of the baseline clinical and historical features in the two groups were similar.
Conclusion: These data suggest that ipratropium should be combined with initial albuterol nebulization in the ED treatment of acute asthma in adults, especially those with PEFRs less than 200 L/min.