Role of cardiopulmonary exercise testing as a risk-assessment method in patients undergoing intra-abdominal surgery: A systematic review

Abstract

Background: Cardiopulmonary exercise testing (CPET) is used as a preoperative risk-stratification tool for patients undergoing non-cardiopulmonary intra-abdominal surgery. Previous studies indicate that CPET may be beneficial, but research is needed to quantify CPET values protective against poor postoperative outcome [mortality, morbidity, and length of stay (LOS)]. Methods: This systematic review aimed to assess the ability of CPET to predict postoperative outcome. The following databases were searched: PubMed, EMBASE, PEDro, The Cochrane Library, Cinahl, and AMED. Thirty-seven full-text articles were included. Data extraction included the following: author, patient characteristics, setting, surgery type, postoperative outcome measure, and CPET outcomes. Results: Surgeries reviewed were hepatic transplant and resection (n=7), abdominal aortic aneurysm (AAA) repair (n=5), colorectal (n=6), pancreatic (n=4), renal transplant (n=2), upper gastrointestinal (n=4), bariatric (n=2), and general intra-abdominal surgery (n=12). Cardiopulmonary exercise testing-derived cut-points, peak oxygen consumption (V⊙2 peak), and anaerobic threshold (AT) predicted the following postoperative outcomes: 90 day-3 yr survival (AT 9-11 ml kg-1 min-1) and intensive care unit admission (AT <9.9-11 ml kg-1 min-1) after hepatic transplant and resection, 90 day survival after AAA repair (V⊙2 peak 15 ml kg-1 min-1), LOS and morbidity after pancreatic surgery (AT <10-10.1 ml kg-1 min-1), and mortality and morbidity after intra-abdominal surgery (AT 10.9 and <10.1 ml kg-1 min-1, respectively). Conclusions: Cardiopulmonary exercise testing is a useful preoperative risk-stratification tool that can predict postoperative outcome. Further research is needed to justify the ability of CPET to predict postoperative outcome in renal transplant, colorectal, upper gastrointestinal, and bariatric surgery.