326 Cardiopulmonary Exercise Test as Predictor of Postoperative Ileus in Elective Colorectal Surgery – a Prospective Cohort Study

Abstract

Abstract Aim Postoperative ileus (POI) is a complication where there is abnormal pattern of slow or absent gastrointestinal motility after surgery. Elderly, frail, and comorbid patients often undergo cardiopulmonary exercise test (CPET) to determine their risks and suitability for major surgery. A literature review on Pubmed and Web of Science reveal no studies have been published on whether CPET variables can act as a predictor of POI. Hence, we aim to investigate whether there is a correlation between CPEX and post-operative ileus or major complications after colorectal surgery. Method All patients with stage I-IV Colorectal cancer who underwent CPET test between January 2013-June 2021 before elective major colorectal surgery were enrolled. Anaerobic threshold (AT) was used as a marker of cardiopulmonary fitness on CPET. POI was defined in any patient with NGT inserted postoperatively. Major complications were classified using Clavien-Dindo Classification≥Grade 3. Fisher’s exact test was used for categorical variables and independent sample t-test for continuous variables. Results In total, 115 patients were included - 64% were males and median age was 78(51-95) years old. Mean Anaerobic threshold was 10.4(6.4-15.6) mg/kg/min. Thirty-three(29%) and fifteen(13%) patients experienced POI and major complications respectively. There were no significant differences in mean AT for those who had POI versus without (10.9 vs 10.2, p = 0.13) and those with major complications versus without (10.7 vs 10.4, p = 0.62). Conclusions The overall incidence of POI was relatively high. Our study did not confirm level of cardiorespiratory fitness as a predictor of postoperative ileus or major complications.