Rest PETCO2 as a Predictor of Post-operative Complications

Cardiopulmonary exercise testing (CPET) is considered to be a golden standard in preoperative risk assessment and stratification of high risk patients scheduled for major surgery. However, not all of the patients requiring surgery are willing or able to complete this type of testing. Vascular surgery patients are predominantly elderly people, with significant comorbidity and high degree of frailty and often can not undergo CPET. In recent years, new parameters with similar prognostic value as standard CPET parameters were studied. Specifically, the partial pressure of end-tidal carbon dioxide (PETCO2) at rest has been shown to have the same prognostic value as ventilatory efficiency. We hypothesized low PETCO2 at rest will be associated with the development of pulmonary and cardiovascular post-operative complications in patients after major vascular surgery. Accordingly, our aim is to compare PETCO2 measured at rest before surgery in patients who develop post-operative complications and in those who do not.