Risk Factors for Postoperative Ileus after Elective Colorectal Surgery

Purpose: The aim of this study was to determine whether various patient characteristics and perioperative clinical interventions might be correlated with the incidence of postoperative ileus (POI). Methods: We prospectively investigated 114 patients who were scheduled to undergo elective colorectal surgery. The associations of patient characteristics and clinical interventions with POI were examined statistically. We also included preoperative stress as a possible predictor of POI. Results: A total of 11 (9.7%) patients developed POI. Univariate analyses showed that an intraoperative remifentanil dose of ≥4.0mg was significantly associated with the occurrence of POI. Although a multivariate analysis showed that only an intraoperative remifentanil dose of ≥4.0 mg was statistically correlated with the occurrence of POI (p=0.0375), the risk for POI increased significantly with the number of other predictive factors present: a male sex, and an intraoperative remifentanil dose of ≥4.0 mg. A correlation between preoperative stress and the incidence of POI was not found. Conclusions: Our study suggests that an intraoperative remifentanil dose of ≥4.0 mg is a risk factor for POI and that the risk increases when it coexists with a male sex. Further study is needed to clarify the correlations among a male sex, intraoperative remifentanil use, and the incidence of POI.