Coagulation disorders after traumatic brain injury

Background. Over the past decade new insights in our understanding of coagulation have identified the prominent role of tissue factor. The brain is rich in tissue factor, and injury to the brain may initiate disturbances in local and systemic coagulation. We aimed to review the current knowledge on the pathophysiology, incidence, nature, prognosis and treatment of coagulation disorders following traumatic brain injury (TBI). Methods. We performed a MEDLINE search from 1966 to April 2007 with various MESH headings, focusing on head trauma and coagulopathy. We identified 441 eligible English language studies. These were reviewed for relevance by two independent investigators. A meta-analysis was performed to calculate the frequencies of coagulopathy after TBI and to determine the association of coagulopathy and outcome, expressed as odds ratios. Results. Eighty-two studies were relevant for the purpose of this review. Meta-analysis of 34 studies reporting the frequencies of coagulopathy after TBI, showed an overall prevalence of 32.7%. The presence of coagulopathy after TBI was related both to mortality (OR 9.0; 95%CI: 7.3-11.6) and unfavourable outcome (OR 36.3; 95%CI: 18.7-70.5). Conclusions. We conclude that coagulopathy following traumatic brain injury is an important independent risk factor related to prognosis. Routine determination of the coagulation status should therefore be performed in all patients with traumatic brain injury. These data may have important implications in patient management. Well-performed prospective clinical trials should be undertaken as a priority to determine the beneficial effects of early treatment of coagulopathy.