Effect of Inspiratory Muscle Training on Respiratory Muscle in Patients Undergoing Open Heart Surgery

Author(s): Chitima Kulchanarat, Suphannee Choeirod, Supattra Thadatheerapat, Dusarkorn Piathip, Opas Satdhabudha, Kornanong Yuenyongchaiwat

Background: Patients undergoing open-heart surgery (OHS) are at risk of postoperative pulmonary complications and decreased functional capacity (FC) of the lungs. Respiratory muscle training (RMT) is reported to be effective in improving respiratory muscles strengthening (RMS) and FC. Aim: To investigate the effects of RMT on the respiratory muscles of patients undergoing OHS. Design: A randomized controlled trial Setting: Thammasat University Hospital Population: Patients undergoing OHS. Methods: Fifty-eight patients who underwent OHS were randomly assigned to two groups: 29 in the control group (CG) and 29 in the training group (TG). The patients in the TG underwent physical therapy program and RMT using a breath trainer. Patients in the CG underwent physical therapy only. The maximum inspiratory pressure (MIP), maximum expiratory pressure (MEP) and 6-minute walk test (6MWT) were assessed pre- and post-operatively. Results: The TG had significant increase in MIP (46.70±24.98 vs. 61.40±28.46 cmH2O, P<0.001), MEP (40.06±22.83 vs. 62.30±22.64 cmH2O, P<0.001) and 6-MWT (172.73±88.11 vs. 208.26±89.42 m, P=0.013). The CG had significant decrease in MIP (42.23±20.26 vs. 23.46±9.94 cmH2O, P<0.001), MEP (35.90±24.35 vs. 23.10±15.03 cmH2O, P=0.002) and 6MWT (150.83±91.79 vs. 76.6±67.67 m, P<0.001). Conclusion: RMT effectively improved RMS and FC in patients undergoing OHS.