Deep venous thrombosis: clinically silent in the intensive care unit.
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.
Crowther
Mark A
MA
Department of Medicine, McMaster University, Hamilton, Ontario, Canada L8N 3Z5.
Cook
Deborah J
DJ
Griffith
Lauren E
LE
Devereaux
Phillip J
PJ
Rabbat
Christian C
CC
Clarke
France J
FJ
Hoad
Neala
N
McDonald
Ellen
E
Meade
Maureen O
MO
Guyatt
Gordon H
GH
Geerts
William H
WH
Wells
Phillip S
PS
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*