The study to be developed from this project aims to evaluate the effect of positive airway expiratory pressure (EPAP) on upper limb exercise-induced dynamic hyperinflation (DH) in patients with chronic obstructive pulmonary disease (COPD). To this end, a cross-over study will be implemented, developed at the Pulmonology Department of Hospital de Clínicas de Porto Alegre. Patients with moderate to very severe, clinically stable COPD will be evaluated. The anthropometric data and pulmonary function will be collected from the medical records, being the study divided into two stages. First stage: At the first visit, dyspnea, quality of life will be evaluated and a maximal incremental cardiopulmonary exercise test (CPET) for upper limb with DH evaluation during exercise. Patients who presented DH on incremental CPET will be invited to return for a second and third visit. In the second and third visit an endurance test will be performed with 80% of the load reached in the incremental CPET and DH determination, one of the tests performed during the application of EPAP through a face mask with pressure level Of 10 cmH2O and another in usual breathing, with the mask without the use of the positive pressure generating valve. The sequence of the test, ie, with and without EPAP, will be obtained through electronic randomization. Patients completing stage 1 will be invited to enter step 2. In this step, which will occur in a single visit, patients will perform a 6-minute pegboard and ring test (6PBRT) with The same monitoring of CPET in three different situations, according to randomization: habitual breathing, half-closed lip breathing (RLS) and the EPAP mask. Thus, it is expected that the application of EPAP through face mask and the use of RLS will reduce DH during submaximal exercise with upper limb, which will be associated with the reduction of dyspnea and increased tolerance to exercise in COPD patients .
