Prolonged postoperative ileus-definition, risk factors, and predictors after surgery

Postoperative ileus (POI) remains an inevitable consequence of abdominal surgery. Although the pathogenesis of delayed gastrointestinal transit in the postoperative period has been the subject of considerable study, a clinically useful definition of what constitutes a pathologically prolonged ileus has yet to be established. The objectives of this study were to describe a definition for an abnormally prolonged ileus and to identify risk factors and predictors of prolonged ileus in patients undergoing abdominal surgery.

Over a 12-month period 88 patients who had abdominal surgery were retrospectively reviewed. The association of clinical factors with the duration of POI was examined with statistical tests.

The mean time to commencing the consumption of unrestricted clear fluids after surgery was 2.3 +/- SD 1.6 days. The median duration of POI was 5 days (median 6 days), with an interquartile range of 3-6 days. Univariate regression analysis demonstrated significant correlations between duration of POI and estimated blood loss (EBL), total surgical time, and total opiate dose (TOD) (p = 0.009, p = 0.045, and p = 0.041, respectively). Multiple regression analysis identified EBL and TOD as independent predictors of duration of POI.

We have identified two risk factors (EBL and TOD) that are independently associated with duration of POI. Our data suggest that with the definition of abnormal prolonged postoperative ileus as the number of days above the 3rd quartile, an ileus greater than 6 days serves as a better clinical definition of prolonged POI than 3 days, the measure that has previously been suggested.