Effects of Aerosolized Surfactant in Patients With Stable Chronic Bronchitis

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Abstract
Context. —Chronic bronchitis, estimated to affect more than 13 million adults in the United States, is characterized in part by retention of airway secretions, but no approved or effective therapy for airway mucus retention in patients with chronic bronchitis has been established. Surfactant reduces sputum adhesiveness, which contributes to difficulty in clearing secretions, but surfactant has not been tested in patients with chronic bronchitis. Objective. —To examine the effects of exogenous surfactant on sputum clearance and pulmonary function in patients with stable chronic bronchitis. Design. —A prospective, multicenter, randomized, double-blind, parallel-group, placebo-controlled comparison of the effects of 2 weeks of treatment with 3 doses of aerosolized surfactant (palmitoylphosphadidylcholine [DPPC]) or saline (placebo). Setting. —Four US teaching hospitals. Participants. —A total of 87 adult patients with the diagnosis of stable chronic bronchitis. Main Outcome Measures. —Pulmonary function, respiratory symptoms, and sputum properties before treatment (day 0), after 2 weeks of treatment (day 14), and 7 days after stopping treatment (day 21). Reslts. —A total of 66 patients were randomized to surfactant treatment and 21 to saline treatment. Patient demographic characteristics between groups were similar at baseline. In patients who received a DPPC dose of 607.5 mg/d for 2 weeks, prebronchodilator forced expiratory volume in 1 second (FEV1) increased from 1.22 L (SEM, 0.08 L) at day 0 to 1.33 L (SEM, 0.09 L) at day 21 (P=.05), an improvement of 11.4%; postbronchodilator FEV1improved 10.4% by days 14 and 21 (P=.02); and the ratio of residual volume to total lung capacity, a measure of thoracic gas trapping, decreased 6.2% by day 21 (P=.009). In the surfactant groups, there was a dose-dependent increase in the ability of sputum to be transported by cilia in vitro. Conclusion. —Aerosolized surfactant improved pulmonary function and resulted in a dose-related improvement in sputum transport by cilia in patients with stable chronic bronchitis.