title: Risk modification for postoperative pulmonary embolism: timing of postoperative prophylaxis.
abstract: BACKGROUND
  Risk factors for postoperative pulmonary embolism can often not be modified and are patient related. The purpose of this case control study was to identify possible modifiable risk factors for postoperative pulmonary embolism.
  
  
  METHODS
  We undertook a case control study among 210,269 patients who underwent noncardiac surgery from 2000 to 2009 at the Erasmus Medical Center. Case subjects were all 199 (0.09%) patients who experienced a pulmonary embolism within 30 days after surgery. From the remaining patients, 1 control was selected for each case and was stratified according to calendar year. For cases and controls, information was obtained regarding risk factors and the type and dose of thromboprophylaxis as well as the time of postoperative initiation.
  
  
  RESULTS
  Overweight, surgery for malignancy, a history of cerebrovascular disease and a history of thromboemblic diseases, intraoperative blood transfusions and delayed use of thromboprophylaxis were more common in cases than in controls. After correction delayed use of thromboprophylaxis was associated with a 4 fold increased risk (OR 4.1; 95% CI: 2.1 - 7.7) for postoperative pulmonary embolism.
  
  
  CONCLUSIONS
  Delayed timing of postoperative thromboprophylaxis is an important modifiable risk factor for postoperative pulmonary embolism after noncardiac surgery. This study emphasises the importance of on time administration of thromboprophylaxis.
authors.affiliation: Department of Anesthesiology, Erasmus Medical Center, Rotterdam, The Netherlands. f.vanlier@erasmusmc.nl
authors.forename: Felix
authors.initials: F
authors.lastname: van Lier
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: van der Geest
authors.forename: Jaap W
authors.initials: JW
authors.lastname: Hol
authors.forename: Frank W
authors.initials: FW
authors.lastname: Leebeek
authors.forename: Sanne E
authors.initials: SE
authors.lastname: Hoeks
mesh_terms: D004334:Drug Administration Schedule; D005260:Female; D005343:Fibrinolytic Agents / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D011183:Postoperative Complications / Q000453:epidemiology* / Q000517:prevention & control*; D011184:Postoperative Period; D015995:Prevalence; D011655:Pulmonary Embolism / Q000453:epidemiology* / Q000517:prevention & control*; D040242:Risk Reduction Behavior; D016896:Treatment Outcome
chemical_list: D005343:Fibrinolytic Agents