Hirudin versus heparin for anticoagulation in continuous renal replacementtherapy

Objective: To compare the efficacy and safety of hirudin and heparin for an ticoagulation during continuous renal replacement therapy (CRRT) in critica lly ill patients. Design: Prospective, randomized controlled pilot study. Setting: Single centre; interdisciplinary intensive care unit at a universi ty hospital. Patients: Seventeen patients receiving CRRT. Interventions: Patients were randomly allocated to two groups. Heparin grou p (nine patients): continuous administration of 250 IU/h heparin; dose was adjusted in 125 IU/h steps with a targeted activated clotting time (ACT) of 180-210 s. Hirudin group (eight patients): continuous infusion of 10 mug/k g/h hirudin, dose was adjusted in 2 mug/kg/h steps with a targeted ecarin c lotting time (ECT) of 80-100 s, Observation time was 96 h. Measurements and main results: Measured filter run patency and haemofiltrat ion efficacy did not significantly differ between the two groups. Three ble eding complications were observed in the hirudin group, none in the heparin group (P < 0.01). At the onset of bleeding, which occurred 60 or more hour s after the start of therapy, only one patient was still under continuous h irudin administration but levels were either in therapeutic range or below. Conclusions: Hirudin can be used efficiently for anticoagulation in CRRT. L ate bleeding complications may have been caused by possible hirudin accumul ation, but this was not evident from hirudin plasma and ECT levels. Since b leeding complications were observed only in the presence of documented coag ulation disorders, not only adequate drug monitoring but also the plasmatic and cellular coagulation status of the patient should be taken into consid eration for adjusting hirudin dosage.