Respective Contributions of Head and Extra-Head Injury Severities to the Occurrence of Early Coagulopathy Following Traumatic Brain Injury

The respective weights of head and extra-head injuries to the occurrence of coagulopathy following traumatic brain injury (TBI) remain unclear. We hypothesized that the severity of extra-head injuries would be the main contributor to coagulopathy following TBI. This was a retrospective study from a multicenter, prospective trauma registry. All adult patients directly admitted following TBI (Abbreviated Injury Score [AIS]) head ≥1) from 2012 to 2021 were included. Coagulopathy was defined as a prothrombin time ratio (PTr) >1.2, platelets <100 G.L -1 , or fibrinogen level <1.5 g.L -1 on hospital admission. TBI severity was assessed by the Glasgow Coma Scale (GCS). Severe extracranial injuries were defined by at least one of the extra-head AIS scores ≥3 (AIS extra-head ≥3). Incidences of coagulopathy were determined and compared according to TBI severity in patients with or without severe extracranial injuries. Risk factors for coagulopathy were identified using bivariate analysis and then multivariable analysis. In 9,610 TBI patients analyzed, the overall incidence of coagulopathy was 28.5% ( n = 2,738). The incidence of coagulopathy increased gradually with TBI severity, from 8% for GCS 14–15% to 42% for GCS 3 in patients without severe extracranial injuries, and from 27% for GCS 14–15% to 70% for GCS 3 in patients with severe extracranial injuries. In multivariable analysis, AIS extra-head ≥3 (odds ratio = 2 [1.8–2.3], p < 0.001) and GCS ≤8 (odds ratio = 1.3 [1.1–1.6], p = 0.001) were independent risk factors for coagulopathy. Coagulopathy was associated with both head and extra-head injury severities, yet to a greater extent with severe extracranial injuries.