title: Hypercoagulability and other risk factors in trauma intensive care unit patients with venous thromboembolism.
abstract: BACKGROUND
  Thromboelastography (TEG) on hospital admission can identify hypercoagulable trauma patients at risk for venous thromboembolism (VTE), but the value of TEGs obtained after multiple interventions, including tranexamic acid (TXA), has not been defined. We test the following hypotheses. (1) TEG on intensive care unit (ICU) admission can help stratify patients screened with Greenfield's risk assessment profile (RAP) for VTE. (2) TXA is a VTE risk factor, and its effect on fibrinolysis can be identified with TEG.
  
  
  METHODS
  Trauma patients who survived to the ICU with RAP ≥ 10 received serial venous duplex ultrasound examinations and blood samples for coagulation analysis at admission to the ICU and weekly thereafter.
  
  
  RESULTS
  Six hundred seventy-eight patients were screened and 121 were enrolled; 76% blunt injury, Injury Severity Score (ISS) 27, 13% mortality. Thromboprophylaxis was administered to 90% of the patients and was started a median of 2 days after hospital admission. VTE was detected in 28% (n = 34) of the patients (27 deep vein thrombosis and 7 pulmonary emboli) and occurred a median 10 days after admission. Twenty-nine percent (n = 10) of VTE occurred within 2 days of admission. Most variables were similar between those with and without VTE, but the VTE group received more operations (3 (2) vs. 2 (2), p = 0.044), had increased ICU days (25 (34) days vs. 15 (18) days, p = 0.004), and was more likely to have abdominal injury with Abbreviated Injury Scale (AIS) score > 2 (59% vs. 39%, p = 0.050). Upon ICU admission, standard coagulation markers were within normal limits, while TEG demonstrated hypercoagulability, but neither was associated with VTE. Repeat TEG one week after admission (n = 58) remained hypercoagulable but transitioned to a different pattern with increased clot strength. TXA was associated with reduced fibrinolysis on initial TEG (p < 0.05) but was not associated with VTE.
  
  
  CONCLUSIONS
  Trauma ICU patients with RAP ≥ 10 are hypercoagulable at admission to ICU and remain so during recovery. They have a ≥ 25% rate of VTE, despite thromboprophylaxis. TXA is associated with reduced fibrinolysis but does not increase VTE rates. Neither TEG nor standard coagulation markers (measured on ICU admission) stratify high-risk patients who develop VTE from those who do not.
  
  
  METHODS
  Prognostic study, level III.
authors.affiliation: From the Dewitt-Daughtry Family Department of Surgery, University of Miami Miller School of Medicine and Ryder Trauma Center, Miami, Florida.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Van Haren
authors.forename: Evan J
authors.initials: EJ
authors.lastname: Valle
authors.forename: Chad M
authors.initials: CM
authors.lastname: Thorson
authors.forename: Jassin M
authors.initials: JM
authors.lastname: Jouria
authors.forename: Alexander M
authors.initials: AM
authors.lastname: Busko
authors.forename: Gerardo A
authors.initials: GA
authors.lastname: Guarch
authors.forename: Nicholas
authors.initials: N
authors.lastname: Namias
authors.forename: Alan S
authors.initials: AS
authors.lastname: Livingstone
authors.forename: Kenneth G
authors.initials: KG
authors.lastname: Proctor
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000627:therapeutic use; D001780:Blood Coagulation Tests; D015331:Cohort Studies; D003422:Critical Care; D005260:Female; D005500:Follow-Up Studies; D017052:Hospital Mortality; D006801:Humans; D007362:Intensive Care Units; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D018570:Risk Assessment; D012720:Severity of Illness Index; D016019:Survival Analysis; D013916:Thrombelastography / Q000379:methods; D019851:Thrombophilia / Q000150:complications / Q000175:diagnosis*; D014193:Trauma Centers; D015599:Trauma Severity Indices; D016896:Treatment Outcome; D018616:Ultrasonography, Doppler, Duplex; D054556:Venous Thromboembolism / Q000175:diagnosis* / Q000188:drug therapy / Q000209:etiology / Q000401:mortality*; D014947:Wounds and Injuries / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy; D055815:Young Adult
chemical_list: D000925:Anticoagulants