Aims and Objectives Traumatic brain injury is suspected of inducing coagulopathy but the evidence to support this is conflicting. Systemic analyses in isolated TBI (ITBI) have not consistently demonstrated a functional coagulation deficit. While guidelines recognise the need to emergently reverse anticoagulant therapy, no guideline recommends routine coagulation testing in ITBI, and there are no published algorithms for treatment of any ITBI associated coagulopathy.

We hypothesized that there is a specific coagulopathy of ITBI, detectable using functional coagulation tests and that coagulopathy is associated with worse outcomes including raised intracranial pressure (ICP), progression of intracranial haemorrhage (PICH), and mortality.

Method and Design We retrospectively analysed admission laboratory and ROTEM tests from patients with ITBI (head Abbreviated Injury Score of 3 or more and below 3 in all other body regions) who were enrolled in the prospective observational Activation of Coagulation and Inflammation in Trauma study (REC 07/Q0603/2). Basal cistern compression (BCC) was considered a surrogate for raised intracranial pressure.

Results and Conclusion 237 patients had a severe ITBI. At least one coagulation abnormality was present in 66% of individuals EXTEM CA5<40mm (45%), EXTEM ML<5% (44%), d-dimer>30,000 (38%), fibrinogen<2g/L (38%) and EXTEM CT>80s (29%), aPTT (7%). Coagulation abnormalities were more common in those with more severe injuries, head AIS 5 versus AIS 3 (70% vs 62%) and BCC (81% vs 64%). The presence of any abnormality was associated with BCC (35% vs 18%), 7-day PICH (67% vs 51%) and higher 7-day mortality (21% vs 7.5%). Several admission tests were good or excellent predictors of BCC (d-dimer AUROC 0.832, fibrinogen AUROC 0.745) and 7-day mortality (aPTT AUROC 0.781, FIBTEM CT AUROC 0.717).

Admission ITBI coagulopathy is common and associated with head injury severity and radiological evidence of BCC. The presence of admission coagulopathy was predictive of mortality and basal cistern compression.