Development of a risk stratification system for the occurrence of prolonged postoperative ileus after colorectal surgery: a prospective risk factor analysis.
BACKGROUND
Management strategies for prolonged postoperative ileus (PPOI) are principally conservative and it is therefore valuable to shift attention to prevention. This study aimed to identify prospectively the perioperative risk factors for the development of PPOI and create a tool to predict its occurrence.


METHODS
Patients undergoing elective colorectal surgery at Auckland District Health Board between September 2012 and June 2014 were enrolled. In total, 92 variables were investigated prospectively with uniform application of a standardized definition of PPOI. Logistic regression and area under receiver operating characteristic curves (AUC) were used to generate risk stratification models.


RESULTS
PPOI occurred in 88 of 327 patients (26.9%). Independent predictors of PPOI were male gender (odds ratio [OR], 3.01), decreasing preoperative albumin (OR, 1.11 per g/L unit), open or converted technique (OR, 6.37 [vs laparoscopic]), increasing wound size (OR, 1.09 [per cm]), operative difficulty (OR, 1.28 [per unit on 10-point Likert scale]), operative bowel handling (OR, 1.38 [per unit on 10-point Likert scale]), red cell transfusion (OR, 1.84 [per unit]), intravenous crystalloid administration (OR, 1.55 [per liter]), and delayed first mobilization (OR, 1.39 [per day]). The I-Score assimilated preoperative and intraoperative variables to generate a score out of 6 with a 7-fold increase in risk from low-risk to high-risk strata and fair predictive capacity (AUC, 0.742; 95% CI, 0.684-0.799).


CONCLUSIONS
Independent predictors for the development of PPOI have been identified prospectively and used to construct a novel risk stratification model.
Department of Surgery, University of Auckland, Auckland District Health Board, Auckland, New Zealand.
Ryash
R
Vather
Department of Surgery, University of Auckland, Auckland District Health Board, Auckland, New Zealand.
Rachel
R
Josephson
Department of Surgery, University of Auckland, Auckland District Health Board, Auckland, New Zealand.
Rebekah
R
Jaung
Department of Surgery, University of Auckland, Auckland District Health Board, Auckland, New Zealand.
Jason
J
Robertson
Department of Surgery, University of Auckland, Auckland District Health Board, Auckland, New Zealand; Colorectal Unit, Department of Surgery, Auckland District Health Board, Auckland, New Zealand. Electronic address: i.bissett@auckland.ac.nz.
Ian
I
Bissett
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003107:Colorectal Surgery; D003661:Decision Support Techniques; D017558:Elective Surgical Procedures; D005260:Female; D006801:Humans; D045823:Ileus / Q000175:diagnosis / Q000209:etiology*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D059035:Perioperative Period; D011183:Postoperative Complications / Q000175:diagnosis / Q000209:etiology*; D011446:Prospective Studies; D012372:ROC Curve; D018570:Risk Assessment; D012307:Risk Factors; D055815:Young Adult