Purpose: The optimal dose of albuterol to use in the treatment of acute asthma has yet to be established. The National Asthma Education and Prevention Program (NAEPP) recommends a starting dose of 2.5 to 5 mg of aerosolized albuterol every 20 min, although European authorities recommend higher doses. The purpose of this study was to compare 2.5 vs 7.5 mg of nebulized albuterol for the treatment of acute asthma.
Subjects: We studied 160 patients presenting to the emergency department with acute asthma.
Methods: On enrollment, patients underwent baseline testing, including initial spirometry. All patients received prednisone, 60 mg, orally. Patients then received in a randomized, double-blinded fashion, nebulized albuterol either 2.5 or 7.5 mg every 20 min for a total of three doses. Spirometry was repeated after each of the first two treatments and again 40 min after completion of the three treatments.
Results: The pretreatment FEV1 was 36.9+/-16.6% of predicted normal in the low-dose group vs 41.5+/-15.4% of predicted normal in the high-dose group (not significant [NS]). The patients in the low-dose group had a 50.3+/-62.6% improvement in FEV1 pretreatment to post-treatment, whereas those in the high-dose group had a 44.6+/-48.2% improvement in FEV1 (NS). There was no difference in the admission rate in the low-dose group (43%) as compared with that of the high-dose group (39%; NS).
Conclusion: We conclude that there is no advantage to the routine administration of doses of albuterol higher than 2.5 mg every 20 min. It is possible that there may be an advantage in the most severely obstructed patients, although this study did not enroll enough patients with very severe asthma to evaluate this. As has been previously demonstrated, patients who subsequently require admission have a diminished response to albuterol. This decreased responsiveness is seen with the first aerosol administration and is unaffected by increasing the dose.