Feasibility of preoperative inspiratory muscle training in patients undergoing coronary artery bypass surgery with a high risk of postoperative pulmonary complications:: a randomized controlled pilot study

Objective: To determine in a pilot study the feasibility and effects of preoperative inspiratory muscle training in patients at high risk of postoperative pulmonary complications who were scheduled for coronary artery bypass graft surgery. Design: Single-blind, randomized controlled pilot study. Setting: University Medical Centre Utrecht, the Netherlands. Subjects: Twenty-six patients at high risk of postoperative pulmonary complications were selected. Intervention: The intervention group (N = 14) received 2-4 weeks of preoperative inspiratory muscle training on top of the usual care received by the patients in the control group. Main measures: Primary outcome variables of feasibility were the occurrence of adverse events, and patient satisfaction and motivation. Secondary outcome variables were postoperative pulmonary complications and length of hospital stay. Results: The feasibility of inspiratory muscle training was good and no adverse events were observed. Treatment satisfaction and motivation, scored on 10-point scales, were 7.9 (+/-0.7) and 8.2 (+/-1.0), respectively. Postoperative atelectasis occurred in significantly fewer patients in the intervention group than in the control group (chi(2)(DF1) = 3.85; P = 0.05): Length of hospital stay was 7.93 (+/-1.94) days in the intervention group and 9.92 (+/-5.78) days in the control group (P = 0.24). Conclusion: Inspiratory muscle training for 2-4 weeks before coronary artery bypass graft surgery was well tolerated by patients at risk of postoperative pulmonary complications and prevented the occurrence of atelectasis in these patients. A larger randomized clinical trial is warranted.