Safety and Efficacy of Prophylactic Enoxaparin Adjusted by Anti-Factor Xa Peak Levels in Pancreatic Surgery

Background Recommended prophylactic doses of enoxaparin (Lovenox) are associated with subprophylactic anti-Factor Xa (anti-Xa) levels. This study examines the safety and efficacy of anti-Xa-guided dosing of enoxaparin in pancreatic surgery. Methods Prospectively enrolled patients undergoing pancreatic surgery received enoxaparin dosing adjusted based on peak anti-Xa levels and were compared to a historical cohort of patients. Results Baseline characteristics were similar between the intervention and control groups. In the intervention group, 73.9% initially had subprophylactic peak anti-Xa levels. There were no differences in the venous thromboembolism (VTE) rates between the intervention and control groups (0% vs. 7.69%; P = .084), major bleeding events (4.35% vs. 2.56%; P = .627), RBC transfusion (15.2% vs. 25.6%; P = .257), or Hgb on discharge (9.82 vs. 9.44 g/dL; P = .244). Subtherapeutic anti-Xa levels were correlated with a higher BMI ( P = .033), longer OR time ( P = .011), and length of stay ( P = .018). Conclusions Enoxaparin 40 mg once daily is associated with subprophylactic peak anti-Xa levels. Dose adjustment based on anti-Xa levels trended toward a lower rate of in-hospital VTE without an increase in bleeding or transfusion requirement.