Abstract Background Cardiac surgery causes pathophysiological changes that favor the occurrence of pulmonary and functional complications. Objective To investigate the effects of inspiratory muscle training (IMT) with an electronic device on patients undergoing cardiac surgery. Methods A randomized controlled trial was conducted with 30 adult patients undergoing elective cardiac surgery. A control group (CG) received conventional physical therapy care, and an intervention group (IG) received IMT using the POWERbreathe K5® electronic device. Two daily sessions of physical therapy were performed at the intensive care unit and one daily session at the ward until the sixth postoperative day. The following variables were measured preoperatively and on the sixth postoperative day, in both groups: inspiratory muscle strength, dynamic inspiratory muscle strength, and peak inspiratory flow. Data distribution was evaluated by the Shapiro-Wilk test. Analysis of variance was used, and the results were considered statistically significant when p < 0.05. Results Maximal inspiratory pressure (71.7 ± 17.1 cmH2O vs 63.3 ± 21.3 cmH2O; p = 0.11], S-index (52.61 ± 18.61 vs 51.08 ± 20.71), and peak inspiratory flow [(2.94 ± 1.09 vs 2.79 ± 1.26)] were maintained in the IG but had a significant reduction in the CG. Conclusion IMT performed with an electronic device was effective at maintaining inspiratory muscle strength, dynamic inspiratory muscle strength, and peak inspiratory flow when compared to conventional physical therapy. Int J Cardiovasc Sci. 2020; [online].ahead print, PP.0-0

Abstract Introduction: Cardiac surgery is a highly complex procedure which generates worsening of lung function and decreased inspiratory muscle strength. The inspiratory muscle training becomes effective for muscle strengthening and can improve functional capacity. Objective: To investigate the effect of inspiratory muscle training on functional capacity submaximal and inspiratory muscle strength in patients undergoing cardiac surgery. Methods: This is a clinical randomized controlled trial with patients undergoing cardiac surgery at Instituto Nobre de Cardiologia. Patients were divided into two groups: control group and training. Preoperatively, were assessed the maximum inspiratory pressure and the distance covered in a 6-minute walk test. From the third postoperative day, the control group was managed according to the routine of the unit while the training group underwent daily protocol of respiratory muscle training until the day of discharge. Results: 50 patients, 27 (54%) males were included, with a mean age of 56.7±13.9 years. After the analysis, the training group had significant increase in maximum inspiratory pressure (69.5±14.9 vs. 83.1±19.1 cmH2O, P=0.0073) and 6-minute walk test (422.4±102.8 vs. 502.4±112.8 m, P=0.0031). Conclusion: We conclude that inspiratory muscle training was effective in improving functional capacity submaximal and inspiratory muscle strength in this sample of patients undergoing cardiac surgery.