Dose-response characteristics of nebulized albuterol in the treatment of acutely ill, hospitalized asthmatics

We investigated the bronchodilator dose-response to nebulized albuterol and the dose of albuterol which produces maximal bronchodilation in the acutel y ill, hospitalized asthmatic. Consecutively admitted patients from the eme rgency room in status asthmaticus who fulfilled the inclusion criteria (age <41 years old and <12 pack-years of smoking) were studied. Albuterol was a dministered by nebulizer (Puritan-Bennett Raindrop) in:repeated 2.5-mg trea tments up to a total dose of 10 mg and the bronchodilator response was meas ured by a computerized spirometer. Twenty-two patients were studied. Baseli ne spirometry showed a (mean +/- SE) forced expiratory volume in 1 sec (FEV 1) of 1.26 +/- 0.14 L (42 +/- 4.0% predicted), which increased significantl y (p < 0.05) during albuterol titration to a maximum FEV1 of 1.70 +/- 0.19 L (57 +/- 5% of predicted). After cumulative doses of 2.5, 5.0, 7.5, and 10 .0 mg of nebulized albuterol, 27%, 45%, 72%, and 77% of patients, respectiv ely, attained maximum bronchodilation. The remaining 23% of patients did no t respond to doses up to 10 mg of albuterol. The maximum FEV, response to a lbuterol did not correlate with the initial severity of airflow obstruction (r = 0.36, p > 0.05). Pulse rate and arterial oxygen saturation were not s ignificantly affected by nebulized albuterol up to a total dose of 10 mg. N o arrhythmias were noted. In summary, most hospitalized asthmatics (72%) re quired a cumulative dose of 7.5 mg of nebulized albuterol to achieve maximu m bronchodilation and a large fraction (50%) required higher albuterol dose s than the standard 2.5 mg. The bronchodilatory response to nebulized albut erol varied widely among patients in status asthmaticus and could not be pr edicted from the initial severity of airflow obstruction. Because side effe cts were minimal, it would be reasonable to use 7.5 mg of nebulized albuter ol as initial therapy. Alternatively, dose-response titration with albutero l would be advantageous.