Single-center Experience with Venous Thromboembolism Prophylaxis for Obese Burn Patients

Burn injured patients are at high risk of thromboembolic complications. Morbid obesity further increases this risk. Our objective was to evaluate the efficacy of enoxaparin dosed 40 mg twice daily in achieving prophylactic plasma anti-Xa levels in obese burn patients. A retrospective chart review from November 2018 until September 2019 identified patients who were either ≥100 kg or had a body mass index ≥30 kg/m2 and initiated on enoxaparin 40 mg twice daily for venous thromboembolism prophylaxis. Patients were ≥18 yr of age and received ≥3 sequential doses of enoxaparin with appropriately timed peak plasma anti-Xa levels to monitor efficacy. One hundred forty-eight patients were screened with 43 patients included for analysis. Forty-two percent of the patients did not reach target peak plasma anti-Xa levels (0.2-0.5 IU/ml) on enoxaparin 40 mg twice daily. Patients who did not meet prophylactic target levels were more likely to be male (P < 0.05) and have an increased mean body weight (129 ± 24 kg vs 110 ± 16 kg, P < 0.05). Thirteen out of 18 patients received dosage adjustments with subsequent anti-Xa levels available for follow-up assessment, of which an additional six patients required further dosage adjustment to meet prophylactic goals. Current utilization of a fixed 40 mg twice daily regimen of enoxaparin for venous thromboembolism (VTE) is inadequate to meet target prophylactic peak plasma anti-Xa levels in the obese burn patient population. Dose adjusting enoxaparin to target anti-Xa levels to reduce VTE rates in obese burn patients should be further evaluated.