Early posttraumatic changes in coagulation and fibrinolysis systems in isolated severe traumatic brain injury patients and its influence on immediate outcome.

OBJECTIVE/BACKGROUND: Early coagulopathy in isolated severe traumatic brain injury occurs despite the lack of severe bleeding, shock, and fluid administration. We aimed to correlate coagulation activation/inhibition, thrombin generation and fibrinolysis with the development of acute trauma induced coagulopathy (TIC) and its effects on early mortality in isolated severe traumatic brain injury (iSTBI) patients.

METHODS: A prospective screening of iSTBI patients was done for two years. History of anticoagulants, liver disease, hypotension, extracranial injuries, transfusion, brain death were excluded. TIC was defined as international normalized ratio (INR) ≥ 1.27 and/or prothrombin time (PT) ≥ 16.7 seconds and/or activated partial thromboplastin Time (aPTT) ≥ 28.8 seconds on admission following iSTBI. Analysis of tissue factor (TF), tissue factor pathway inhibitor (TFPI), protein C (PC), protein S (PS), thrombin/antithrombin complex (TAT), soluble fibrin monomer (sFM), tissue plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1) was done. Cases were categorized as presence or absence of TIC and 20 healthy controls participants were included.

RESULTS: A total of 120 cases met the inclusion criteria, aged 35.7 ± 12.12 years, 96% males. TIC was identified in 50 (41.6%). TIC occurred independently of age, sex, Glasgow coma scale (GCS) but was associated with acidosis (60%; p = .01). Following iSTBI significant decline was seen in coagulation activation. Thrombin generation and fibrinolysis were markedly increased. TF, TFPI, PC and PS were low in TIC compared with control. Significant depletion of PS was seen in TIC versus No-TIC. TBI patients with depleted PS had an odds ratio (OR) of 7.10 (1.61-31.2) for TIC. Receiver operating characteristic curve (ROC) analysis depicted area under the curve (AUC) of 0.73 (95% confidence interval [CI] 0.63-0.84) with a cut-off of ≥74 of PS (specificity 63.9%, sensitivity 72.7%). In-hospital mortality was higher in TIC group (44%) compared with no-TIC (20%) with OR of 4.73 (95% CI 1.68-13.3) and hazard ratio [HR] of 2.8 (95 % CI 1.2-6.4).

CONCLUSION: Incidence of TIC in iSTBI is 41.6%, with 4.7 times odds for mortality. Traumatic brain injury causes enhanced coagulation activation, inadequate inhibition, exacerbation of thrombin generation, and subsequent increased fibrinolysis. ROC curve analysis revealed a cut-off of PS ≤ 74 with specificity 63.8%, sensitivity 72.7% for development of TIC.