Objective: The purpose of this study was to investigate the effect of prophylactic anticoagulation on the incidence of venous thromboembolic events (VTE) in patients suffering from isolated severe traumatic brain injury (TBI).
Materials and methods: Retrospective matched case-control study in adult patients sustaining isolated severe TBI (head AIS ≥3, with extracranial AIS ≤2) receiving VTE prophylaxis while in the surgical intensive care unit from 1/2007 through 12/2009. Patients subjected to VTE prophylaxis were matched 1:1 by age, gender, glasgow coma scale (GCS) score at admission, presence of hypotension on admission, injury severity score, and head abbreviated injury scale (AIS) score, with patients who did not receive chemical VTE prophylaxis. The primary outcome measure was VTE. Secondary outcomes were SICU and hospital length of stay (HLOS), adverse effects of anticoagulation, and mortality.
Results: After propensity matching, 37 matched pairs were analysed. Cases and controls had similar demographics, injury characteristics, rate of craniotomies/craniectomies, SICU LOS, and HLOS. The median time of commencement of VTE prophylaxis was 10 days. The incidence of VTE was increased 3.5-fold in the controls compared to the cases (95% CI 1.0-12.1, P=0.002). The mortality was higher in patients who did not receive anticoagulation (19% vs. 5%, P=0.001). No adverse outcomes were detected in the anticoagulated patients.
Conclusion: Prophylactic anticoagulation decreases the overall risk for clinically significant VTE in patients with severe isolated TBI. Prospective validation of the timing and safety of chemical VTE prophylaxis in these instances is warranted.
Keywords: Anticoagulation; isolated severe head injury; mortality; traumatic brain injury; venous thromboembolic event.