Abstract
BACKGROUND: The recommended treatment of COPD exacerbations includes administration of short-acting bronchodilators that act to reverse bronchoconstriction, restore lung volumes, and relieve breathlessness. In vitro studies demonstrate vibrating mesh nebulizers (VMNs) provide greater drug delivery to the airway compared to standard small-volume nebulizers (SVNs). We examined whether the physiological and symptom response to nebulized bronchodilators during a COPD exacerbation differed between these 2 modes of bronchodilator delivery. METHODS: Subjects hospitalized with a COPD exacerbation participated in a comparative clinical effectiveness study of 2 methods of nebulization. Using block randomization, 32 participants in this open-label trial were administered salbutamol 2.5 mg/ipratropium bromide 0.5 mg via vibrating mesh (VMN group, n = 16) or small-volume jet nebulizer (SVN group, n = 16) on one occasion. Spirometry, body plethysmography, and impulse oscillometry were performed and Borg breathlessness scores recorded pre bronchodilator and at 1 h post bronchodilator. RESULTS: Baseline demographics were comparable between groups. Mean FEV(1) was 48% predicted. Significant changes in lung volumes and airway impedance were seen in both groups. Inspiratory capacity (IC) increased by 0.27 ± 0.20 L and 0.21 ± 0.20 L in the VMN and SVN group, respectively, between group difference P = .40. FVC increased in the VMN group by 0.41 ± 0.40 L compared to 0.19 ± 0.20 L with SVN, between group difference P = .053; and residual volume (RV) decreased by 0.36 ± 0.80 L and 0.16 ± 0.50 L in the VMN and SVN group, respectively, between group difference P = .41. The VMN group had a significant reduction in Borg breathlessness score, P = .034. CONCLUSIONS: Greater improvement in symptoms, and larger absolute change in FVC, was observed in response to equivalent doses of standard bronchodilators administered by VMN, compared to SVN, but no substantial difference in change in IC.