Safety and efficacy of prophylactic anticoagulation in patients with traumatic brain injury.

BACKGROUND: Patients with traumatic brain injury (TBI) are at high risk for venous thromboembolism (VTE), but physicians are cautious with chemical prophylaxis in these patients because of concern about exacerbating intracranial hemorrhage. We hypothesized that early use of chemical thromboprophylaxis would reduce VTE incidence without increasing intracranial hemorrhage. STUDY
DESIGN: Records of all patients admitted with a TBI to a Level I trauma center from 2006 to 2008 were reviewed. TBI was defined as intracranial hemorrhage, hematoma, contusion, or diffuse axonal injury with a head Abbreviated Injury Scale score >2. Patients were excluded if they were discharged or died within 72 hours of admission. Chemical prophylaxis was defined as subcutaneous or intravenous unfractionated heparin or low molecular weight heparin before any VTE diagnosis. Progression of TBI was defined by worsening CT findings. VTE was defined as deep venous thrombosis or pulmonary embolus confirmed by radiology reports. Primary outcomes were progression of hemorrhage and VTE events.
RESULTS: Eight hundred and twelve of the 1,258 patients admitted to the trauma center with a TBI met study criteria. Chemical thromboprophylaxis was given to 49.5% (n = 402). Mean head Abbreviated Injury Scale score was 3.4 in both groups. One hundred and sixty-nine patients started prophylaxis within 48 hours and 242 patients began within 72 hours. Patients receiving chemical prophylaxis had a lower incidence of VTE (1% versus 3%; p = 0.019). Although not statistically significant, they also had a lower rate of injury progression, 3% versus 6% (p = 0.055).
CONCLUSIONS: Use of chemical thromboprophylaxis in TBI patients with a stable or improved head CT after 24 hours substantially reduces the incidence of VTE and does not increase the risk of progression of intracranial hemorrhage.