Prophylactic Enoxaparin Dosing Using Anti-Factor Xa Levels in Hepatic Surgery Patients: A Pilot Study

This study examines the safety and efficacy of using peak anti-Xa levels to achieve prophylactic enoxaparin (Lovenox, Sanofi-Aventis) levels in patients who underwent hepatic surgery. Prospectively enrolled patients undergoing major and minor hepatic procedures received postoperative enoxaparin dosing. The enoxaparin dose was adjusted to attain a peak anti-Xa level ≥ 0.20 U/ml. This group was compared to a historical cohort of patients who underwent similar procedures and received standard postoperative VTE chemoprophylaxis dosing. Inpatient postoperative VTE rates were higher in the control group when compared to the experimental group (0 patients [0.00%] vs 4 patients [8.16%]; P = .035). There was no statistically significant difference in number of postoperative blood transfusions, discharge hemoglobin, or in-hospital bleeding events. Adjusting enoxaparin dosing to achieve prophylactic peak anti-Xa levels of ≥0.20 IU/ml was associated with a reduced incidence of symptomatic inpatient postoperative VTE in patients who underwent hepatic surgery without increasing postoperative bleeding events.