Prognostic Value of Effort-independent Cardiopulmonary Exercise Test Variables for Postoperative Complications After Elective Colorectal Surgery

A cardiopulmonary exercise test (CPET) is increasingly used for preoperative risk assessment. Oxygen uptake (VO2) at peak exercise (VO2peak) and VO2 at the ventilatory anaerobic threshold (VO2VAT) are the most commonly used preoperative CPET variables that are associated with postoperative outcomes following colorectal cancer surgery. The aim of this study is to investigate the association between preoperative submaximal and effort-independent CPET variables and postoperative outcomes in colorectal cancer surgery. Specifically, the slope of the relation between minute ventilation and carbon dioxide production (VE/VCO2-slope) and the oxygen uptake efficiency slope (OUES) will be investigated.