A Weight- and Anti-Xa-Guided Enoxaparin Dosing Protocol for venous thromboembolism Prophylaxis in intensive care unit Trauma Patients.

ABSTRACT

BACKGROUND: Trauma patients are high risk for venous thromboembolism (VTE) and the optimal dosing strategy for prophylactic enoxaparin remains unknown. The purpose of this quality improvement project was to evaluate a weight-based and anti-Xa-guided enoxaparin dosing protocol in intensive care unit (ICU) trauma patients and to determine if the protocol led to reduced clinical VTE rates. MATERIALS AND METHODS: Adult trauma patients admitted for ≥ 48 hours to our surgical or neurosurgical ICUs who received ≥ 3 consecutive weight-based enoxaparin doses were eligible for inclusion into this pre-post implementation cohort study. Enoxaparin 30 mg every 12 hours was used for weight 50 to 100 kg and body mass index (BMI) < 40 kg/m2 and enoxaparin 40 mg every 12 hours for weight ≥ 100 kg or BMI ≥ 40 kg/m2. PRE cohort patients did not routinely receive anti-Xa level monitoring, while in the POST cohort, dosing was subsequently titrated to peak anti-Xa levels of 0.2 to 0.4 IU/mL. RESULTS: A total of 110 and 113 patients were included in the PRE and POST cohorts, respectively. Clinical VTE rates were similar between groups. In the POST cohort, 75% of patients achieved goal anti-Xa levels without dose titrations, while 12% of higher weight patients and 9.1% of lower weight patients required adjustment. When comparing weight quartiles, patients > 100 kg were more likely to have sub-prophylactic anti-Xa levels than those ≤ 69 kg. CONCLUSIONS: Our enoxaparin dosing protocol was safe and frequently achieved initial anti-Xa levels within goal, indicating that weight-based dosing alone may be sufficient. However, patients > 100 kg may benefit from anti-Xa monitoring as they are highest risk for sub-prophylactic levels despite higher initial enoxaparin dosing.