Introduction
POSTOPERATIVE COMPLICATIONS
Preoperative aerobic fitness is independently associated with postoperative outcomes following major abdominal surgery [During CPET, a patient exercises against a progressively increasing work rate until volitional exhaustion, while breath-by-breath respiratory gasses are analyzed. The large number of data-points that are collected by the breath-by-breath sampling rate can be a challenge for data visualization, as the signal can have high variability. Therefore, data-averaging is performed to optimize graphical data display and to aid CPET interpretation (see Visualization of the plot with oxygen uptake (VOThe most frequently used CPET-derived variables that are associated with postoperative complications in the current literature are the oxygen uptake at peak exercise (VOAlthough preoperative risk assessment should be multimodal, CPET-derived thresholds are often used to recognize patients with a low aerobic fitness who have a high risk for adverse surgical outcomes. In major abdominal surgery, often used thresholds to identify patients at high-risk for postoperative complications are a VO2peak <18.2 mL/kg/min and/or a VO2VAT <11.1 mL/kg/min [