Soluble Fibrin and DDimer as Detectors of Hypercoagulability in Patients with Isolated Brain Trauma

To test the hypothesis that hypercoagulability after brain trauma was related to the severity of injury and also to outcome, new coagulation markers were used in 20 patients with isolated brain trauma. In addition to routine coagulation tests, soluble fibrin SF, Ddimer, and antithrombin AT levels were assessed. Thirteen of 20 patients had a Glasgow coma score GCS of ≤7 on admission and severe disability SD or worse on the Glasgow outcome scale GOS. Eight patients had a very bad outcome GOS dead D or vegetative V. All patients had increased SF levels ref. <15 nmolL at admission. Six patients with SF <50 nmolL had a good outcome with moderate disability MD or better. Patients with increasingly higher SF levels had a worse outcome Three of five patients with SF 50 to 150 nmolL were severely disabled SD or worse four of six patients with SF >150 nmolL remained vegetative V or died D. Four of the six patients with the highest Ddimer levels at admission remained vegetative V or died D. Six of 13 patients with a significant drop in AT levels had a bad outcome D or V whereas only two of seven patients without AT consumption did poorly. Routine coagulation studies were often pathologic, i.e., reduced platelet count, but there was no relation to outcome. Increased SF and Ddimer levels at admission followed by a secondary decrease in AT concentration and platelets seem to be good markers of the posttraumatic hypercoagulation often seen after brain injury. There was a significant relation between SF levels, severity of brain injury GCS, and subsequent outcomes GOS in severely headinjured patients.