Admission thrombelastography does not guide dose adjustment of enoxaparin in trauma patients

Abstract

Background: Enoxaparin is used as chemoprophylaxis to reduce incidence of venous thromboembolism and its complications following trauma. Serum anti-Xa monitoring is used to assess efficacy but requires several doses to be administered. Thrombelastography assesses hypercoagulability and may have utility identifying high-risk patients for venous thromboembolism. The objective was to evaluate whether thrombelastography parameters could identify trauma patients requiring enoxaparin dose adjustment earlier than serum anti-Xa concentrations. Methods: A single-center, retrospective medical record review evaluated patients admitted to a regional level I trauma center that received an admission thrombelastography and a dose of enoxaparin with a serum trough anti-Xa concentration drawn. Patients were divided into standard-dose or dose-adjusted enoxaparin. Venous thromboembolism incidence between groups and risk factors for enoxaparin dose adjustment and venous thromboembolism development were evaluated. Results: A total of 204 patients were included. Differences observed between groups included age (standard-dose enoxaparin, 48.5 [29.3–72] vs dose-adjusted enoxaparin, 38.5 [25–55.7] years; P = .005), admission creatinine clearance (standard-dose enoxaparin, 92.9 [67.4–113.4] vs dose-adjusted enoxaparin, 102.1 [83.8–129.2] mL/min; P = .017), and time to venous thromboembolism prophylaxis initiation (standard-dose enoxaparin, 23.8 [11.2–36.4] vs dose-adjusted enoxaparin, 34.5 [18.3–52.7] hours; P = .004). No differences in thrombelastography parameters or venous thromboembolism incidence were observed. No independent risk factors for enoxaparin dose adjustment were identified; however, risk assessment profile score > 10 was an independent risk factor for venous thromboembolism development. Conclusion: No relationship between admission thrombelastography and need for enoxaparin dose adjustment in trauma patients was observed. As thrombelastography continues growing in clinical use, it is prudent to investigate other potential applications. Currently, thrombelastography should not be used to guide enoxaparin dosing.