Thromboelastography (TEG) has been recommended to characterize post-traumatic coagulopathy, yet no study has evaluated the impact of pre-injury anticoagulation (AC) on TEG variables. We hypothesized patients on pre-injury AC have a greater incidence of coagulopathy on TEG compared to those without AC.

This retrospective chart review evaluated all trauma patients admitted to an urban, level one trauma center from February 2011 to September 2014 who received a TEG within the first 24h. Patients were classified as receiving pre-injury AC or no AC if their documented medications prior to admission included warfarin, dabigatran, or anti-Xa (aXa) inhibitors (apixaban or rivaroxaban). The presence of coagulopathy on TEG or conventional assays was defined by exceeding local laboratory reference standards.

A total of 54 patients were included (AC, n=27 [warfarin n=13, dabigatran n=6, aXa inhibitor n=8] vs. no AC, n=27). Baseline characteristics were similar between groups, including age (72±13years vs. 72±15; p=0.85), male gender (70% vs. 74%; p=0.76) and blunt mechanism of injury (100% vs. 100%; p=1). There was no difference in the number of patients determined to have coagulopathy on TEG (no AC 11% vs. AC 15%; p=0.99). Conventional tests, including the international normalized ratio (INR) and activated partial thromboplastin time (aPTT), identified coagulopathy in a high proportion of anti-coagulated patients (no AC 22% vs. AC 85%; p<0.01).

TEG has limited clinical utility to evaluate the presence of pre-injury AC. Traditional markers of drug induced coagulopathy should guide reversal decisions.