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 € for heparin and enoxaparin, respectively.

Conclusion  

Enoxaparin can be safely used for anticoagulation during CVVH resulting in higher filter lifespan compared with unfractionated heparin.