Emergency department treatment of severe asthma. Metered-dose inhaler plus holding chamber is equivalent in effectiveness to nebulizer

Abstract

Study objective: To compare the effectiveness of administration of albuterol by nebulizer or by a metered-dose inhaler having a holding chamber attachment (hereafter "inhaler") for treatment of acute asthma in an emergency department (ED).

Design: A randomized, double-blind, placebo-controlled intervention study conducted at two sites.

Setting: The EDs of a large municipal hospital and a university teaching hospital.

Patients: Thirty-five patients 10 to 45 years of age seeking treatment at an ED for acute asthma.

Interventions: Patients were randomly assigned to receive either albuterol by nebulizer plus placebo by inhaler (n = 20) or albuterol by inhaler plus placebo by nebulizer (n = 15). The dose was repeated every 30 min until the FEV1 was at least 80 percent of predicted, the patient became asymptomatic, or 6 doses had been given.

Measurements and results: All references in this article to spirometric measurements of forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), and peak expiratory flow rate (PEFR) represent percentages of the predicted normal value. No significant (p > 0.58) differences occurred in baseline mean FEV1, FVC, or PEFR for the two groups. For both groups, significant improvement occurred in mean FEV1 at 30 min (p < 0.02) and at 60 min (p < 0.02), and in maximum mean FEV1 (p < 0.001). However, no significant (p > 0.6) differences occurred between groups in mean FEV1, FVC, or PEFR at 30 and 60 min, or in maximum improvement attained. The sample size was sufficiently large to detect a 12 percent difference in improvement with a power of 90 percent. Thirty-three of 35 patients were treated successfully with the study protocol, became asymptomatic, and were discharged home. One patient from each group required further treatment.

Conclusions: There was no detectable difference in effectiveness of albuterol administered by nebulizer or the inhaler system for treatment of acute asthma. There was no detectable difference in effectiveness of albuterol administered by nebulizer or the inhaler system for the treatment of acute asthma when the dose was titrated to clinical response. When compared with nebulizer, the metered-dose inhaler with holding chamber delivers a full dose of albuterol more quickly and at no higher cost.