Objective: The purpose of this study was to evaluate the efficacy and safety of the low molecular weight heparin enoxaparin as anticoagulant in continuous veno-venous hemofiltration (CVVH) compared with unfractionated heparin.
Design: Prospective randomized controlled crossover study.
Setting: Medical and Surgical Intensive Care Unit of a University Hospital.
Patients: Forty consecutive adult medical and surgical ICU patients with normal anticoagulation parameters requiring CVVH.
Intervention: CVVH was performed with pre-filter fluid replacement at 2500 ml/h and blood flow rates of 180 ml/min. Heparin-treated patients received an initial pre-filter bolus of 30 IU/kg and a maintenance infusion at 7 units/kg h(-1), titrated to achieve a systemic activated partial thromboplastin time (aPTT) of 40-45 s. Enoxaparin-treated patients received an initial pre-filter bolus of 0.15 mg/kg and a maintenance infusion starting at 0.05 mg/kg h(-1), which was subsequently adjusted to maintain systemic anti-factor Xa activity (anti-Xa) at 0.25-0.30 IU/ml. Each patient received both regimens in a crossover design. Maximum treatment duration for each set was 72 h.
Results: Patients included had a mean APACHE II score of 22 (10-35). Thirty-seven patients completed both study arms. Mean filter life span was 21.7 h (+/- 16.9 h) for heparin and 30.6 h (+/- 25.3) for enoxaparin (p = 0.017, ANOVA for repeated measures). One major bleeding episode occurred during heparin as well as during enoxaparin treatment. Cost analysis showed average daily costs of 270 and 240 euro for heparin and enoxaparin, respectively.
Conclusion: Enoxaparin can be safely used for anticoagulation during CVVH resulting in higher filter lifespan compared with unfractionated heparin.