The rate of deep vein thrombosis doubles in trauma patients with hypercoagulable thromboelastography

Abstract

Background: Venous thromboembolism (VTE) in trauma can occur in patients at low risk. Conventional coagulation tests do not predict VTE. Studies investigating thromboelastography (TEG) for VTE risk are conflicting and have not included routine surveillance to detect deep vein thrombosis (DVT). We undertook a prospective study of TEG to evaluate its utility in predicting VTE.

Methods: We conducted a prospective cohort study on all adult trauma patients admitted to our Level I trauma center from 2013 to 2015. TEG was performed immediately on arrival to the trauma bay. Hypercoagulable TEG was defined as reaction time (R) below, angle (α) above, or maximum amplitude (MA) above reference ranges. All patients received mechanical and/or pharmacologic prophylaxis and were followed up for DVT with our ultrasound surveillance protocol. The primary outcome was lower-extremity DVT. After bivariate analysis of variables related to DVT, those with p values of 0.100 or less were included for multivariate logistic regression.

Results: A total of 983 patients were evaluated with TEG on admission; of these, 684 (69.6%) received at least one surveillance ultrasound during the index admission. Lower-extremity DVT was diagnosed in 99 (14.5%) patients. Hypercoagulability based on admission TEG occurred in 582 (85.1%) patients. The lower-extremity DVT rate was higher in patients with hypercoagulable TEG than in those without hypercoagulable TEG (15.6% vs. 8%; p = 0.039). Multivariate analysis showed hypercoagulable TEG remained associated with DVT after adjustment for relevant covariates available at admission, with an odds ratio of 2.41 (95% confidence interval, 1.11-5.24; p = 0.026).

Conclusion: Most trauma patients were hypercoagulable at admission and remained at risk of developing DVT. The rate of DVT doubled in patients with hypercoagulable TEG indices despite prophylaxis. Beyond its current clinical roles, TEG is useful for assessing DVT risk, particularly in patients otherwise perceived to be at low risk.

Level of evidence: Prognostic study, level II.