Effectiveness of Inspiratory Muscle Training on Respiratory Muscle Strength in Patients Undergoing Cardiac Surgeries: A Systematic Review With Meta-Analysis

To determine the effect of inspiratory muscle training (IMT) on pulmonary function, respiratory muscle strength (RMS), and functional capacity in patients undergoing cardiac surgery. The PubMed, PEDro, CINAHL, Web of Science, CENTRAL, and EMBASE databases were searched from inception to June 2020. Randomized controlled trials (RCTs) that evaluated patients who underwent cardiac surgery were included in this review. Meta-analysis performed using a random-effects model showed that the mean difference in forced vital capacity, forced expiratory volume in 1 second, 6-minute walk distance, and RMS was 3.47% (95% confidence interval [CI], 0.57 to 6.36), 5.80% (95% CI, 2.03 to 9.56), 78.05 m (95% CI, 60.92 to 95.18), and 4.8 cmH(2)O (95% CI, -4.00 to 13.4), respectively. There is strong evidence that IMT improves inspiratory muscle strength, pulmonary function, and functional capacity, and reduces the length of hospital stay in patients undergoing cardiac surgery.