(1006) Evaluation of a Weight-Based Venous Thromboembolism Prophylaxis Protocol in Burn Patients

Introduction: Data has suggested that standard doses of enoxaparin for venous thromboembolism (VTE) prophylaxis may be inadequate in burn patients based on subtherapeutic peak anti-Xa (AXA) levels. Weight-based enoxaparin dosing has been proposed to address this issue. The burn service updated its VTE prophylaxis guideline to incorporate weight-based dosing in 2022. The purpose was to determine enoxaparin dosing requirements needed to achieve a goal AXA level for VTE prophylaxis.

Methods: This retrospective analysis was conducted at an academic dedicated burn center. Adult patients on the burn service who achieved a goal peak AXA level (0.2-0.4 IU/mL) with 3 or more doses of prophylactic enoxaparin from January to December 2023 were included. Initial enoxaparin dosing for patients below 90 kg was 30 mg every 12 hrs. Incrementally higher initial doses were recommended at 90 kg (40 mg), 130 kg (60 mg) and 180 kg (80 mg). AXA monitoring and dose adjustments were done in patients with >20% total body surface area (TBSA) burn and in patients who weighed ≥ 90kg. The primary outcome was the enoxaparin dose required to reach the first goal AXA level. Secondary outcomes included the number of enoxaparin dosing adjustments required and the median time from the start of enoxaparin prophylaxis to goal AXA level. Descriptive statistics were performed.

Results: The analysis included 109 hospital admissions during the study period. The median age was 48 years (IQR 35-62), and 71% were males. Median baseline weight was 96 kg (82-110). Median %TBSA burn was 9% (4-20). The initial median enoxaparin dose was 30 mg (30-40) every 12 hrs. The initial enoxaparin dose was correct in 62% of admissions. The median time to start enoxaparin from admission was 7.6 hrs (4.4-13.9). At goal AXA level, the median enoxaparin dose was 40 mg (40-40), and the weight-based dose was 0.43 mg/kg (0.37-0.5) every 12 hrs. A dosing adjustment was required in 52% of admissions with a median of 1 (0-1) adjustment required. The median time from the first dose of enoxaparin to the first goal AXA level was 3.2 days (1.5-6.1).

Conclusions: The median dose of enoxaparin needed to achieve a goal AXA level was 0.43 mg/kg every 12 hours in our adult burn population. Most patients required at least 1 dosing adjustment to reach goal levels.