A randomized comparison of atropine and metaproterenol inhalational therapies for refractory status asthmaticus

Abstract

Study objective: To compare the forced expiratory volume in one second (FEV1) response to inhaled anticholinergic with the response to beta-adrenergic solutions in adults with refractory status asthmaticus.

Design: After the decision was made to hospitalize, 40 patients were prospectively randomized in a double-blind trial to receive either atropine sulfate or metaproterenol by nebulizer.

Setting: A county teaching hospital emergency department.

Type of participants: Adults requiring hospitalization for refractory status asthmaticus.

Interventions: Standard therapies for acute bronchospasm, followed by either 1.5 mg atropine or 15 mg metaproterenol by nebulizer.

Measurements and main results: The two groups were similar on entry into the study, including mean FEV1 measurements (0.70 L atropine/0.60 L metaproterenol, P greater than .05). Compared with baseline, The FEV1 improvement for the metaproterenol group was statistically significant (+ 0.18 L, P = .05; + 31%, P less than .05), whereas the improvement with atropine did not reach significance (+0.09 L or +10%, P greater than .05). Comparing the two groups, statistically significant differences favoring metaproterenol were found in the percent improvement in the FEV1 (+10% atropine/+31% metaproterenol, P less than .05) and in the percentage of patients experiencing at least a 15% decrease in their FEV1 below baseline (35% atropine/10% metaproterenol, P less than .05). No patient suffered adverse side effects.

Conclusion: For the majority of adults with refractory status asthmaticus, an additional beta-adrenergic inhalation treatment results in greater FEV1 improvement than that resulting from the addition of an atropine inhalation.