To evaluate the efficacy of aerosolized adrenaline compared to inhaled β₂ agonists in the treatment of acute asthma in the emergency setting.

MEDLINE, EMBASE, CINAHI, and Cochrane databases, review articles, and references of included trials.

Published (1966-2005) randomized controlled trials with pulmonary function as primary outcome.

Six studies met the criteria for inclusion in the meta-analysis. They included 161 adults and 121 children and adolescents. Patients who received inhaled adrenaline showed a nonsignificant improvement in pulmonary function (standardized mean difference = 0.20, 95% confidence interval −0.22 to 0.63, P = .35) compared to patients getting inhaled β₂ agonists. Moderate heterogeneity was identified between studies (I² = 47.2%). Homogeneity was achieved when studies that reported pulmonary function were stratified by intensity of adrenaline treatment. The use of more than 2 mg of adrenaline per dose was equivalent to 5 mg of salbutamol or terbutaline per dose. On the contrary, 2 mg or less of adrenaline per dose was inferior to 2.5 or 5 mg of salbutamol per dose. In addition, there were no differences in heart rate and Pao₂ between treatments.

There was no statistically significant benefit of nebulized adrenaline over salbutamol or terbutaline in the treatment of children and adults with moderate-severe acute asthma.