Study objectives: To determine the efficacy of albuterol by metered-dose inhaler (MDI) and spacer compared to a nebulizer.
Design: A prospective, open-label study.
Setting: Large urban emergency department (ED).
Patients: All consecutive adult asthma patients over a 2.5-year period.
Interventions: ED personnel used a standardized treatment algorithm, which included albuterol administered by nebulization, for patients presenting to the ED during the first 12 months of the study. The treatment algorithm then was switched to one that utilized albuterol administered by MDI/spacer as the primary mode of delivery for the following 18 months. As part of the conversion to MDI/spacer, ED staff counseled patients on self-management and supplied patients with a peak flowmeter, an MDI/spacer, and an inhaled steroid for home use.
Measurements: Pulmonary function, clinical outcome, laboratory data, and financial data were assembled and analyzed from 2,342 ED visits and 1,420 patients.
Results: While there was no significant difference in hospital admission rates between patients in the MDI/spacer group and the nebulizer group (13.2% and 14.6%, respectively), there was a statistically greater improvement in peak flow rates in the MDI/spacer group (126.8 vs 111.9 L/min, respectively; p = 0.002). The MDI/spacer group also spent significantly less time in the ED (163.6 and 175 min, respectively; p = 0.007), had a lower total albuterol dose (1,125 microg and 6,700 microg, respectively; p < 0.001), and showed a greater improvement in arterial oxygen saturation (p = 0.043). Relapse rates at 14 and 21 days were significantly lower (p < 0.01 and p < 0.05, respectively) among patients treated with the MDI/spacer and were associated with asthma education and the provision of a peak flowmeter, a spacer, and an inhaled corticosteroid for patients' home use.
Conclusions: Albuterol administered by MDI/spacer is an efficacious and cost-effective alternative to nebulization in adults with acute asthma who present at a large urban ED.