Incidence and predictors of prolonged postoperative ileus after colorectal surgery in the context of an enhanced recovery pathway

Background: Prolonged postoperative ileus (PPOI) is common after colorectal surgery but has not been widely studied in the context of enhanced recovery pathways (ERPs) that include interventions aimed to accelerate gastrointestinal recovery. The aim of this study is to estimate the incidence and predictors of PPOI in the context of an ERP for colorectal surgery. Methods: We analyzed data from an institutional colorectal surgery ERP registry. Incidence of PPOI was estimated according to a definition adapted from Vather (intolerance of solid food and absence of flatus or bowel movement for ≥ 4days) and compared to other definitions in the literature. Potential risk factors for PPOI were identified from previous studies, and their predictive ability was evaluated using Bayesian model averaging (BMA). Results are presented as posterior effect probability (PEP). Evidence of association was categorized as: no evidence (PEP < 50%), weak evidence (50–75%), positive evidence (75–95%), strong evidence (95–99%), and very strong evidence (> 99%). Results: There were 323 patients analyzed (mean age 63.5years, 51% males, 74% laparoscopic, 33% rectal resection). The incidence of PPOI was 19% according to the primary definition, but varied between 11 and 59% when using other definitions. On BMA analysis, intraoperative blood loss (PEP 99%; very strong evidence), administration of any intravenous opioids in the first 48h (PEP 94%; strong evidence), postoperative epidural analgesia (PEP 56%; weak evidence), and non-compliance with intra-operative fluid management protocols (3ml/kg/h for laparoscopic and 5ml/kg/h for open; PEP 55%, weak evidence) were predictors of PPOI. Conclusions: The incidence of PPOI after colorectal surgery is high even within an established ERP and varied considerably by diagnostic criteria, highlighting the need for a consensus definition. The use of intravenous opioids is a modifiable strong predictor of PPOI within an ERP, while the role of epidural analgesia and intraoperative fluid management should be further evaluated.