title: Definition, incidence, risk factors, and prevention of paralytic ileus following radical cystectomy: a systematic review.
abstract: BACKGROUND
  Postoperative paralytic ileus (POI) has profound clinical consequences because it represents a substantial burden on both patients and health care resources.
  
  
  OBJECTIVE
  To determine the knowledge base regarding POI in the radical cystectomy (RC) population with an emphasis on preventive measures and risk factors.
  
  
  METHODS
  A systematic literature search of Medline (1966 to February 2011) and a study review were conducted. Eligible studies explicitly reported the incidence of POI and/or at least two quantitative measures of gastrointestinal recovery.
  
  
  RESULTS
  The search identified 727 relevant articles; 77 met eligibility criteria, comprising 13 793 patients. Of these, 21 used explicit definitions of POI, and they varied widely. Across studies, the incidence of POI ranged from 1.58% to 23.5%. Possible risk factors for POI included increasing age and body mass index. Seventeen studies reported effects of an intervention on POI: 3 randomized controlled studies, 11 observational cohort studies with concurrent comparison, and 3 observational cohort studies with nonconcurrent comparison. Gum chewing was associated with shortened times to flatus (2.4 vs 2.9 d; p<0.0001) and bowel movement (BM) (3.2 vs 3.9 d; p<0.001) in one observational cohort study (n=102); omission of a postoperative nasogastric tube (NGT) was associated with shorter time to flatus (4.21 vs 5.33 d; p=0.0001) and shorter length of stay (14.4 vs 19.1 d; p=0.001) in one observational cohort study (n=430); and the routine use of bowel preparation was associated with an increased incidence of POI (5% vs 19%) in another series (n=86). Additionally, readaptation of the dorsolateral peritoneal layer was shown to shorten times to flatus (p=0.016) and times to BM (p=0.011) in one randomized controlled study (n=200).
  
  
  CONCLUSIONS
  The incidence/definition of POI after RC is highly variable. An improved reporting strategy is needed to identify true incidence and risk factors, and to guide future research for both potential preventive and therapeutic interventions.
authors.affiliation: Department of Urology, The University of Texas Health Science Center San Antonio, San Antonio, TX 78229, USA.
authors.forename: Jorge A
authors.initials: JA
authors.lastname: Ramirez
authors.forename: Andrew G
authors.initials: AG
authors.lastname: McIntosh
authors.forename: Robert
authors.initials: R
authors.lastname: Strehlow
authors.forename: Valerie A
authors.initials: VA
authors.lastname: Lawrence
authors.forename: Dipen J
authors.initials: DJ
authors.lastname: Parekh
authors.forename: Robert S
authors.initials: RS
authors.lastname: Svatek
mesh_terms: D000367:Age Factors; D015992:Body Mass Index; D015653:Cystectomy / Q000009:adverse effects*; D006801:Humans; D015994:Incidence; D007418:Intestinal Pseudo-Obstruction / Q000145:classification / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology / Q000517:prevention & control*; D020127:Recovery of Function; D012307:Risk Factors; D009626:Terminology as Topic; D013997:Time Factors; D016896:Treatment Outcome