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

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.

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.

A county teaching hospital emergency department.

Adults requiring hospitalization for refractory status asthmaticus.

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

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.

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.