title: Risk factors for the development of prolonged post-operative ileus following elective colorectal surgery.
abstract: OBJECTIVE
  Prolonged post-operative ileus (PPOI) increases post-operative morbidity and prolongs hospital stay. An improved understanding of the elements which contribute to the genesis of PPOI is needed in the first instance to facilitate accurate risk stratification and institute effective preventive measures. The aim of this retrospective cohort study was to therefore determine the perioperative risk factors associated with development of PPOI.
  
  
  METHODS
  All elective intra-abdominal operations undertaken by the Colorectal Unit at Auckland District Health Board from 1 January to 31 December 2011 were accessed. Data were extracted for an assortment of patient characteristics and perioperative variables. Cases were stratified by the occurrence of clinician-diagnosed PPOI. Univariate and regression analyses were performed to identify correlates and independent risk factors, respectively.
  
  
  RESULTS
  Two hundred and fifty-five patients were identified of whom 50 (19.6%) developed PPOI. The median duration for PPOI was 4 days with 98% resolving spontaneously with conservative measures. Univariate analysis identified increasing age; procedure type; increasing opiate consumption; elevated preoperative creatinine; post-operative haemoglobin drop, highest white cell count and lowest sodium; and increasing complication grade as significant correlates. Logistic regression found increasing age (OR 1.032, 95% CI 1.004-1.061; p = 0.026) and increasing drop in pre- to post-operative haemoglobin (OR 1.043, 95% CI 1.002-1.085; p = 0.037) as the only independent predictors for developing PPOI. An important limitation of this study was its retrospective nature.
  
  
  CONCLUSIONS
  Increasing age and increasing drop in haemoglobin are independent predictors for developing PPOI. Prospective assessment is required to facilitate more accurate risk factor analysis.
authors.affiliation: Department of Surgery, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland Mail Centre, Auckland, 1142, New Zealand.
authors.forename: Ryash
authors.initials: R
authors.lastname: Vather
authors.forename: Ian P
authors.initials: IP
authors.lastname: Bissett
mesh_terms: D000368:Aged; D003107:Colorectal Surgery / Q000009:adverse effects*; D017558:Elective Surgical Procedures / Q000009:adverse effects*; D005260:Female; D006801:Humans; D045823:Ileus / Q000175:diagnosis / Q000209:etiology*; D008297:Male; D011183:Postoperative Complications / Q000175:diagnosis / Q000209:etiology*; D012307:Risk Factors; D013997:Time Factors