This is a randomized, double-blind, crossover, placebo-controlled trial. Forty clinically stable bronchiectasis (BCE) patients, all sexes, 18 to 60 years, will be evaluated in two non-consecutive days. On the first day, anamnesis, anthopometric evaluation and lung function will be performed, followed by: Quality of Life Questionnaire-Bronchiectasis, Saint George questionnaire, modified Medical Research Council scale and social and economic status. Then, a cardiopulmonary exercise test (CPET) will be performed and after rest, a brochodilator (BD) or placebo randomization will precede a constant load exercise test (CLET) with the respiratory mechanics assessment (OEP). Finally, the accelerometer will be coupled to the patient for 7 consecutive days, aiming to assess the PAL. On the second day, after one-week washout, the accelerometer will be collected and the patient will repeat the CLET with the respiratory mechanics assessment, at the opposite condition to randomization. The randomization sequence will be generated by computer, and put in sealed and opaque envelopes by a volunteer not involved in the study. The BD or placebo will be administered by a professional not involved in the study, according to the randomization. The evaluator will not have access to information on which intervention (BD or placebo) was given prior to each CLET. A paired (anthropometric and social and economic status) healthy control group will be assessed by spirometry, CPET, and CLET and OEP, for comparing respiratory mechanics. In addition they will also use an accelerometer for 7 consecutive days. BCE patients data of endurance time from CLET, respiratory mechanics from OEP, dyspnea and vital signs will be assessed before and after both BD and placebo CLET. Data about onset of BCE, comorbidities and BCE medication will be collected from the patient's medical record. Data normality will be tested by Kolmogorov-Smirnov. Data comparison will be performed by t test or Wilcoxon and the association by Pearson or Spearman. Categorical data will be analyzed by qui-square test or Fischer. The significance level will be set to 5% for all tests.
The bronchodilators (BD) have been widely used in bronchiectasis (BCE) therapeutic and have been shown to be effective in improving exercise capacity in patients with chronic obstructive pulmonary disease and asthma. However their effect on the exercise capacity of patients with BCE is poorly known. Besides, their respiratory mechanics pattern is also not known neither their physical activity level (PAL). Therefore, the hypothesis of this study is that BD are effective in improving exercise capacity of BCE patients. We aim also to characterize their respiratory mechanics and to evaluate their PAL and its association to their quality of life.