512 Single Center Experience with Venous Thromboembolism Prophylaxis for Obese Burn Patients

Abstract

Abstract Introduction Burn injured patients are at high risk of thromboembolic complications. Morbid obesity further increases risk for thromboembolic complications. Recent evidence supports the use of anti-Xa guided enoxaparin dosing for the prevention of venous thromboembolism (VTE) in high risk populations. Our objective was to evaluate the efficacy of enoxaparin 40mg twice daily in achieving prophylactic plasma anti-Xa levels in obese burn patients. Methods A retrospective chart review of an ABA-verified burn center from November 2018 until September 2019 identified patients who were either ≥100 kilograms (kg) or had a body mass index (BMI) ≥ 30 kg/m2 and were initiated on enoxaparin 40 mg twice daily for VTE prophylaxis. Patients were included if they were at least 18 years of age and received at least three sequential doses of enoxaparin with appropriately timed peak plasma anti-Xa levels to monitor efficacy. Patient demographics were analyzed, as well as body weight, BMI, and total body surface area (TBSA) burn. Statistical analysis was performed with student’s t-test for continuous data and Fischer’s exact test for categorical data. Results During the study period, 148 patients were screened with 44 patients included for analysis. Forty-one percent of the patients evaluated 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 body weight (129 +/- 24 kg versus 112 +/- 17 kg, p< 0.05). Eleven out of 18 patients received dosage adjustments with subsequent anti-Xa levels available for follow-up assessment, of which an additional four patients required further dosage adjustment to meet goal peak plasma levels. Conclusions Current utilization of a fixed 40 mg twice daily regimen of enoxaparin for VTE prophylaxis is inadequate to meet target prophylactic peak plasma anti-Xa levels in the obese burn patient population. Dose adjusting enoxaparin to target peak plasma anti-Xa levels to reduce VTE rates in obese burn patients should be further evaluated. Applicability of Research to Practice This study demonstrates the need for more accurate dosing and evaluation of our dosing practices for VTE prevention. It also demonstrates the importance of having a Burn dedicated pharmacist in facilitating appropriate care.