title: Deep venous thrombosis: clinically silent in the intensive care unit.
abstract: OBJECTIVE
  The reliability of clinical signs and the physical examination in the evaluation of deep venous thrombosis (DVT) in the critically ill is unknown. The purpose of this study was to determine the diagnostic properties of clinical examination for signs of DVT in a cohort of medical-surgical intensive care unit (ICU) patients using screening compression ultrasonography as a reference standard.
  
  
  METHODS
  We prospectively included patients older than 18 years with an expected length of ICU stay of more than 72 hours. Patients underwent bilateral lower limb screening compression ultrasound twice weekly and structured physical examination twice weekly by 2 independent trained research coordinators blinded to the ultrasonography results. We classified patients according to 2 methods: method 1, a DVT Risk Stratification System of 3 categories and method 2, a DVT Risk Score, both of which use the history and physical examination to stratify patients for their risk of DVT.
  
  
  RESULTS
  We included 239 patients in our study, 32 of whom had DVT based on the results of their compression ultrasound. We excluded 7 patients with DVT on ICU admission and 2 who did not undergo any structured examinations. We matched controls with cases (9:1) based on duration of ICU stay. Cases and controls were then allocated to low, moderate, and high risk strata for DVT. Using method 1, the area under the receiver operating characteristic curve (AUC) was 0.57 (95% CI, 0.33-0.78, P = .01). Using method 2, the AUC was 0.59 (95% CI, 0.42-0.75, P = .02). An AUC of 1.0 indicates an ideal test, and AUC of 0.50 indicates a test with no diagnostic utility.
  
  
  CONCLUSIONS
  The history and physical examination for DVT are not useful in detecting lower limb DVT in the ICU.
authors.affiliation: Department of Medicine, McMaster University, Hamilton, Ontario, Canada L8N 3Z5.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Crowther
authors.forename: Deborah J
authors.initials: DJ
authors.lastname: Cook
authors.forename: Lauren E
authors.initials: LE
authors.lastname: Griffith
authors.forename: Phillip J
authors.initials: PJ
authors.lastname: Devereaux
authors.forename: Christian C
authors.initials: CC
authors.lastname: Rabbat
authors.forename: France J
authors.initials: FJ
authors.lastname: Clarke
authors.forename: Neala
authors.initials: N
authors.lastname: Hoad
authors.forename: Ellen
authors.initials: E
authors.lastname: McDonald
authors.forename: Maureen O
authors.initials: MO
authors.lastname: Meade
authors.forename: Gordon H
authors.initials: GH
authors.lastname: Guyatt
authors.forename: William H
authors.initials: WH
authors.lastname: Geerts
authors.forename: Phillip S
authors.initials: PS
authors.lastname: Wells
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D016013:Likelihood Functions; D008297:Male; D015588:Observer Variation; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011655:Pulmonary Embolism / Q000517:prevention & control; D012372:ROC Curve; D018570:Risk Assessment; D016037:Single-Blind Method; D014463:Ultrasonography / Q000379:methods; D020246:Venous Thrombosis / Q000000981:diagnostic imaging* / Q000517:prevention & control*