Thromboelastography is a Marker for Clinically Significant Progressive Hemorrhagic Injury in Severe Traumatic Brain Injury.

Abstract

Coagulopathy in traumatic brain injury (TBI) is associated with increased risk of poor outcomes, but accurate prediction of clinically significant progressive hemorrhagic injury (PHI) in patients with severe TBI remains a challenge. Thromboelastography (TEG) is a real-time test of whole blood coagulation that provides dynamic information about global hemostasis. This study aimed to identify differences in TEG values between patients with severe TBI who did or did not experience clinically significant PHI. This was a single-center retrospective cohort study of adult patients with severe TBI. Patients were eligible for inclusion if initial Glasgow coma scale (GCS) was ≤ 8 and baseline head computed tomography (CT) imaging and TEG were available. Exclusion criteria included receipt of hemostatic agents prior to TEG. PHI was defined as bleeding expansion on CT within 24h associated with 2-point drop in GCS, neurosurgical intervention, or mortality within 24h. The primary endpoint was TEG value differences between patients with and without PHI. Secondary endpoints included differences in conventional coagulation tests (CCTs) between groups. Of the 526 patients evaluated, 141 met inclusion criteria. The most common reason for exclusion was lack of baseline TEG and receipt of reversal product prior to TEG. Sixty-four patients experienced PHI in the first 24h after presentation. K time (2.03min vs. 1.33min, P = 0.035) and alpha angle (65° vs. 69°, P = 0.015) were found to be significantly different in patients experiencing PHI. R time (5.25min vs. 4.71min), maximum amplitude (61mm vs. 63mm), and clot lysis at 30min after maximum clot strength (3.5% vs. 1.7%) were not significantly different between groups. Of the CCTs, only activated partial thromboplastin time (30.3s vs. 27.6s, P = 0.014) was found to be different in patients with PHI. Prolonged K time and narrower alpha angle were found to be associated with developing clinically significant PHI in patients with severe TBI. Despite differences detected in alpha angle, median values in both groups were within normal reference ranges. These abnormalities may reflect pathologic hypoactivity of fibrinogen, and further study is warranted to evaluate TEG-guided cryoprecipitate administration in this patient population.