Pre- and postoperative inspiratory muscle training in patients undergoing cardiac surgery: systematic review and meta-analysis

Objective: To determine the effects of pre- and postoperative inspiratory muscle training on length of postoperative hospital stay and pulmonary function in patients undergoing cardiac surgery. Design and methods: We conducted a systematic search using databases (MEDLINE, CINAHL, EMBASE, PEDro and the Cochrane) to find controlled trials evaluating the effects of pre- and postoperative inspiratory muscle training. Results: Eight studies fulfilled the inclusion criteria. Four were about preoperative inspiratory muscle training (416 patients), three about postoperative inspiratory muscle training (115 patients) and one study about pre- and postoperative inspiratory muscle training (43 patients). Preoperative inspiratory muscle training resulted in improvement in: Reduction in length of postoperative hospital stay of -2days (95% CI -3.4, -0.7, N=302), inspiratory pressure of 16.7cmH(2)O (95% CI 13.8, 19.5, N=386), forced expiratory volume in one second of 3% predicted (95% CI 0.1, 6, N=140), forced vital capacity of 4.6% predicted (95% CI 1.9, 7.4, N=140). Patients that received preoperative training had an inspiratory muscle training reduced risk of postoperative pulmonary complications, (RR=0.6; 95% CI 0.5 to 0.8; P=0.0004, N=386). Postoperative inspiratory muscle training resulted in improvement in inspiratory pressure of 16.5cmH2O (95% CI 4.9, 27.8, N=115), and tidal volume of 185ml (95% CI 19.7, 349.8, N=85). Conclusion: Pre- and postoperative inspiratory muscle training showed to be a beneficial intervention in the treatment of patients undergoing cardiac surgery.