The effect of bronchodilators in the exercise capacity and thoracoabdominal mechanics of subjects with bronchiectasis: a randomized crossover, double-blinded, placebo-controlled trial

Bronchodilators (BD) are prescribed for subjects with bronchiectasis (BCT). BDs improve exercise capacity in subjects with COPD; however, its effect in subjects with BCT remains unknown. Objectives: to evaluate the effect of BD in the exercise capacity and thoracoabdominal mechanics in subjects with BCT. Methods: This randomized crossover, double-blinded, placebo-controlled trial included subjects with BCT clinically stable. Subjects performed a cardiopulmonary exercise test and a constant load exercise test (CLET, 75%Wmax) to assess endurance time (Tlim) concurrently to the thoracoabdominal mechanics. BD or placebo was used in a random order, one week apart. Total and compartmental pulmonary volumes, as well as thoracoabdominal asynchrony (TAA), were evaluated. Tlim time, Borg fatigue (F) and dyspnea (D), and peripheral oxygen saturation (SpO2) were also assessed. Results: Ten subjects were included (48±11yrs, 25.6±4kg/m2). No difference in vital signs, dyspnea and SpO2 was observed before CLET between BD and placebo. At the end of CLET, Tlim and SpO2 were higher using BD compared to placebo (342±119 vs 287±102sec, p Conclusion: BD in subjects with BCT improves exercise capacity and reduces dyspnea and fatigue symptoms. However, the mechanism for such improvement remains unknown.