title: Renal failure as a risk factor for venous thromboembolism in critically Ill patients: a cohort study.
abstract: BACKGROUND
  The relationship between kidney function and venous thromboembolism (VTE) in critically ill patients is not well studied. The main objective of this study was to evaluate this relationship in patients admitted to a medical-surgical intensive care unit (ICU).
  
  
  METHODS
  This was a retrospective study of 798 patients admitted to a tertiary-care ICU and prospectively followed for the development of clinically suspected and radiologically diagnosed deep venous thrombosis or pulmonary embolism. Patients were divided based on admission creatinine and dialysis history into five groups: normal kidney function, RIFLE classes R, I and F (combined=acute kidney injury [AKI]) and endstage renal disease (ESRD). We compared VTE prophylaxis practices and VTE incidence in these groups and evaluated renal failure as a VTE risk factor using multivariate Cox regression analysis.
  
  
  RESULTS
  Of the 798 patients, 27.2% had AKI and 10.1% had ESRD. Unfractionated heparin use was similar in the five groups but enoxaparin use was less frequent in AKI (13.4%) and ESRD (3.8%) patients compared with patients with normal kidney function (39.0%). VTE occurred in 7.6% of patients with normal renal function, 7.8% AKI patients and 2.5% ESRD patients (p=0.22). The adjusted hazard ratios for VTE compared to patients with normal kidney function were 0.35 (95% confidence interval [CI], 0.08-1.47) for RIFLE class R, 1.19 (95% CI, 0.83-1.70) for RIFLE class I, 0.82 (95% CI, 0.59-1.14) for RIFLE class F and 0.71 (95% CI, 0.49-1.02, p=0.06) for ESRD.
  
  
  CONCLUSIONS
  Neither AKI nor ESRD was an independent risk factors for critically ill patients.
authors.affiliation: Intensive Care Department, King Abdulaziz Medical City, Riyadh, Saudi Arabia; College of Medicine, King Saud bin Abdulaziz University for Health Sciences, PO Box 22490, Mail code 1425, Riyadh, 11426, Saudi Arabia. Electronic address: aldorzih@yahoo.com.
authors.forename: Hasan M
authors.initials: HM
authors.lastname: Al-Dorzi
authors.forename: Abdulaziz
authors.initials: A
authors.lastname: Al-Heijan
authors.forename: Hani M
authors.initials: HM
authors.lastname: Tamim
authors.forename: Ghassan
authors.initials: G
authors.lastname: Al-Ghamdi
authors.forename: Yaseen M
authors.initials: YM
authors.lastname: Arabi
mesh_terms: D058186:Acute Kidney Injury / Q000097:blood* / Q000503:physiopathology; D000328:Adult; D015331:Cohort Studies; D016638:Critical Illness; D005260:Female; D006493:Heparin / Q000627:therapeutic use; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011655:Pulmonary Embolism / Q000188:drug therapy / Q000209:etiology* / Q000503:physiopathology; D012189:Retrospective Studies; D012307:Risk Factors; D020246:Venous Thrombosis / Q000188:drug therapy / Q000209:etiology* / Q000503:physiopathology
chemical_list: D006493:Heparin
keywords: Acute kidney injury; Chronic kidney failure; Critically ill; Venous thromboembolism