(1771) Impact of a Weight-Based Enoxaparin Protocol on Achieving Goal Anti-Xa Targets in Trauma Patients

Introduction: Venous thromboembolism is one of the most common complications of trauma. Different dosing strategies for enoxaparin have been utilized over time such as fixed dose or weight based, however, there is growing evidence to support the use of more aggressive and patient specific dosing strategies. The authors’ institution implemented a weight based dosing protocol utilizing anti-Xa monitoring. The purpose of this study was to evaluate the efficacy and safety of a weight based enoxaparin protocol in trauma patients.

Methods: Patients were initiated on enoxaparin 0.5 mg/kg subcutaneously every 12 hours for venous thromboembolism prophylaxis. Peak anti-Xa levels were drawn 4-6 hours after at least the third dose. The target anti-Xa peak level was 0.2 to 0.4 units/mL. This was a retrospective study including adult trauma patients admitted to the trauma service who received 40 mg or higher doses of enoxaparin. The primary endpoint was to assess the percentage of patients with a goal anti-Xa peak level. Secondary endpoints included average time to enoxaparin initiation, incidence of VTE, and incidence of major bleeding.

Results: 249 patients were identified with 112 included in the final study population. 86 patients (76.8%) had a therapeutic anti-Xa peak after initial dose. Fifteen patients (13.4%) had an anti-Xa peak above goal and 11 patients (9.8%) had a peak below goal. No patients experienced a venous thromboembolism or major bleeding event during admission. The average time to enoxaparin initiation was 21.2 hours.

Conclusions: Our study was limited to a single center and was retrospective. The study also did not follow patients after discharge. Our study adds to the growing literature surrounding weight based and patient specific enoxaparin dosing in trauma patients but larger studies remain indicated for a larger sample size.