Effectiveness of preoperative breathing exercise interventions in patients undergoing cardiac surgery: A systematic review

Postoperative pulmonary complications are a common cause of morbidity and mortality in patients undergoing cardiac surgery, leading to an increase in length of hospital stay and healthcare costs. This systematic literature review aims to determine whether patients undergoing cardiac surgery who undergo preoperative breathing exercise training have better postoperative outcomes such as respiratory parameters, postoperative pulmonary complications, and length of hospital stay. Systematic searches were performed in the CINAHL, Cochrane Central Register of Controlled Trials, Cochrane Clinical Answers, Cochrane Database of Systematic Reviews, MEDLINE and MedicLatina databases. Studies were included if they examined adult patients scheduled for elective cardiac surgery, who underwent a preoperative breathing exercise training aimed at improving breathing parameters, preventing postoperative pulmonary complications, and reducing hospital length of stay. This systematic review was based on Cochrane and Prisma statement recommendations in the design, literature search, analysis, and reporting of the review. The search yielded 608 records. Eleven studies met the inclusion criteria. Ten studies were randomized controlled trials and one was an observational cohort study. Data from 1240 participants was retrieved from these studies and meta-analysis was performed whenever possible. A preoperative breathing intervention on patients undergoing cardiac surgery may help improve respiratory performance after surgery, reduce postoperative pulmonary complications and hospital length of stay. However, more trials are needed to support and strengthen the evidence.