Comparison of the Maxair Autohaler to wet nebulizer in patients with acute asthma.

STUDY OBJECTIVE

Patients with acute asthma often have difficulty using a conventional metered-dose inhaler. The Maxair Autohaler (3M Pharmaceuticals; St. Paul, MN) is a hand-held breath-actuated device developed to help patients coordinate drug administration. The study objective is to compare the efficacy of the Autohaler with inhaled beta-agonist administered by wet nebulizer in treating acute asthma exacerbations.

DESIGN

Parallel, randomized, placebo-controlled clinical trial.

SETTING

Emergency department (ED) of a university-affiliated hospital.

PARTICIPANTS

Patients aged 18 to 55 years presenting to the ED with acute asthma and an FEV1 40 to 70% on hospital arrival.

INTERVENTIONS AND MEASUREMENTS

Patients were given either six puffs of the Maxair Autohaler (1,200 microg pirbuterol) plus saline solution by nebulizer (active Autohaler group) or six puffs placebo by Autohaler plus 2,500 microg albuterol via nebulizer (active nebulizer group). Treatment was repeated at 30 and 60 min, with clinical evaluation performed before each treatment and again at 120 min. At 120 min, the protocol was completed.

RESULTS

Twenty-four patients were enrolled, with 5 excluded because of protocol violations. Baseline FEV1 percent predicted values for the active Autohaler group were 53% vs 51% for the active nebulizer group (p=not significant [NS]). At time 120 min, values were 66% for Autohaler and 64% for nebulizer (p=NS). The average time to administer Autohaler was 2.9 min, vs 9.1 min for nebulizer. No patient was excluded because of the inability to use the Autohaler device adequately.

CONCLUSION

In patients with moderate asthma exacerbations, similar improvements in pulmonary function are obtained when beta-agonists are given by either the Maxair Autohaler or a wet nebulizer device.