EFFECTS OF DEVICE-GUIDED BREATHING TRAINING AFTER MYOCARDIAL REVASCULARIZATION

Abstract

Background: Myocardial revascularization is a common surgical intervention for those with coronary artery disease (CAD). However, for individuals who undergo this procedure, there is considerable risk for developing post-operative pulmonary complications (PPCs). Results of some studies suggest device-guided breathing training may prevent PPCs in this population. Purpose: To investigate the effects of device-guided (resistive vs. non-resistive) breathing training on key post-operative outcomes; length of stay (LOS), maximal inspiratory pressure (MIP), peak expiratory flow (PEF), and six-minute walk test (6MWT). Methods: Databases including PubMed, Google Scholar, Ovid MEDLINE, Embase, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, EBSCOhost CINAHL Plus with Full Text, and Scopus were searched to identify and retrieve all relevant references. In addition to direct source searching, references in the bibliographies of key articles and review articles also were reviewed to identify relevant studies. The Physiotherapy Evidence Database (PEDro) scale was used to evaluate each study for quality and risk of bias. Results: Twenty-one studies were identified for inclusion. Resistive breathing training resulted in no change in MIP [4 studies; n=154; SMD=0.01 (95% CI: -0.66, 0.69)] and a small decrease in LOS [4 studies; n=154; SMD=0.19 (95% CI: -0.42, 0.80)]. PEF and 6MWT were not analyzed due to insufficient number of studies. There was no effect of non-resistive breathing training on any parameter. Conclusions: Short-term resistive breathing training shows no benefit for MIP, and minimal benefit for LOS. Importantly, resistive breathing training performed pre-operatively is more effective in improving LOS and MIP compared to post-operative training. Further, low levels of resistive breathing training (i.e., <40% MIP) have no effect on either MIP or LOS. Additional research to compare pre-operative, post-operative versus pre- and post-operative interventions strategies is warranted.