Background: The incidence and risk factors for traumatic brain injury (TBI)-associated coagulopathy after severe TBI (sTBI) and the effect of this complication on outcomes have not been evaluated in any large prospective studies.
Methods: Prospective study of all patients admitted to the surgical intensive care unit (ICU) of an urban, Level I trauma center from June 2005 through May 2007 with sTBI (head Abbreviated Injury Scale score of >or=3). Criteria for TBI-coagulopathy included a clinical condition consistent with coagulopathy, i.e. sTBI, in conjunction with a platelet count <100,000 mm3 and/or elevated international normalized ratio and/or activated partial thromboplastin time. The following potential risk factors with p < 0.2 on bivariate analysis were included in a stepwise logistic regression analysis to identify independent risk factors for TBI coagulopathy and its association with mortality: age, mechanism of injury (blunt [B] or penetrating [P]), presence of hypotension upon admission, Injury Severity Score (ISS), Glasgow Coma Scale (GCS), head and other body area Abbreviated Injury Scale, isolated head injury, diffuse axonal injury, cerebral edema, intracranial hemorrhage (intraventricular, parenchymal, subarachnoid, or subdural), pneumocephalus, and presence of midline shift.
Results: A total of 436 patients (392 blunt, 44 penetrating) met study criteria, of whom 387 patients had isolated SHI. TBI coagulopathy occurred in 36% of all patients (B: 33%, P: 55%; p < 0.0075) and in 34% of patients with isolated head injury (B: 32%, P: 54%; p = 0.0062). Independent risk factors for TBI-coagulopathy in isolated sTBI were found to include a GCS score of <or=8, ISS >or=16, presence of cerebral edema, subarachnoid hemorrhage, and midline shift. ICU lengths of stay were significantly longer in SHI patients who developed TBI coagulopathy (12.7 vs. 8.8 days; p = 0.006). The development of TBI coagulopathy in SHI was associated with increased mortality, adjusted odds ratio (95% confidence interval): 9.61 (4.06-25.0); p < 0.0001.
Conclusion: The incidence of TBI coagulopathy in SHI is high, especially in penetrating injuries. Independent risk factors for coagulopathy in isolated head injuries include GCS score of <or=8, ISS >or=16, hypotension upon admission, cerebral edema, subarachnoid hemorrhage, and midline shift. The development of TBI coagulopathy is associated with longer ICU length of stay and an almost 10-fold increased risk of death.