Effects of a respiratory muscle training protocol with POWERBreathe® in patients undergoing coronary artery bypass grafting with with extracorporeal circulation: randomized clinical trial

Introduction: Cardiovascular diseases can cause physical impairment, with decreased exercise tolerance capacity, in addition to damages to the respiratory (system/tract/strength) and the degree of functional independence, generating a negative impact on the quality of life of patients undergoing myocardial revascularization. Objective: To assess the effects of inspiratory muscle training with POWERBreathe® in patients undergoing myocardial revascularization using cardiopulmonary bypass on the behaviors of respiratory and peripheral muscle strength, exercise capacity, functional independence and quality of life, from hospitalization to follow-up of 30 and 90 days after the surgical procedure. Method: Study approved by the Institutional Research Ethics Committee, Opinion No. 2,195.884 and approved by the Brazilian Registry of Clinical Trials (Registro Brasileiro de Ensaios Clínicos – REBEC) RBR-2p4mz5. This is a clinical, randomized, controlled trial. Seventy patients, aged from 44 to 78 years, were randomized into two groups: control group, with conventional physical therapy (CG, n=34), and intervention group, with conventional physical therapy associated with inspiratory muscle training with an electronic device (IG, n. =36). Respiratory and peripheral muscle strength, capacity and functional independence and quality of life were evaluated preoperatively, 5, 30, and 90 days after surgery. Results: Statistically significant increase in exercise capacity in IG was observed in the follow-up of 90 days after surgery (p = 0.0192), as well as in the quality of life, functional capacity domain, and the follow-up 30 and 90 days after surgery (p = 0.0079). Maximal inspiratory pressure and handgrip strength variables showed a negative correlation, from weak to moderate intensity, in both groups over time. Conclusion: Inspiratory muscle training with POWERBreathe® associated with physical therapy increased the exercise capacity and quality of life of patients undergoing coronary artery bypass graft surgery with cardiopulmonary bypass