Effect of respiratory muscle training on functional capacity related to the quality of life of patients undergoing coronary artery bypass grafting with cardiopulmonary bypass: randomized clinical trial

OBJECTIVE: To evaluate the effects of inspiratory muscle training using POWERbreathe® in patients undergoing myocardial revascularization with extracorporeal circulation, focusing on respiratory and peripheral muscle strength, exercise capacity, functional independence, and quality of life, from hospitalization to a 30 and 90 day followup. METHODS: This randomized controlled clinical trial included 70 patients aged 44-78 years who were randomized into two groups. The Control Group underwent conventional physical therapy (Control Group, n=34), whereas the Intervention Group underwent conventional physical therapy combined with inspiratory muscle training using POWERbreathe® (Intervention Group, n=36). Respiratory and peripheral muscle strength, capacity, functional independence, and quality of life were evaluated preoperatively and 5, 30, and 90 days after surgery. RESULTS: A statistically significant increase in exercise capacity in the Intervention Group was observed 90 days after surgery (p=0.0192), as well as in the functional capacity domain of quality of life at 30 and 90 days after surgery (p=0.0079). The maximal inspiratory pressure and handgrip strength showed a negative correlation, ranging from weak to moderate intensity, in both groups over time. CONCLUSION: Inspiratory muscle training with the POWERBreathe combined with physical therapy improves exercise capacity and quality of life in patients undergoing myocardial revascularization.Prospero database registration: RBR-2p4mz5.