Efficacy and safety of anticoagulation with heparin versus heparin plus epoprostenol in patients undergoing extracorporeal liver support with Prometheus.

Anticoagulation for extracorporeal liver support is delicate due to underlying coagulation disorders in patients with liver failure and to the associated elevated bleeding risk. To date, there has been no detailed report on anticoagulation issues in patients treated with Prometheus, a device based on the principle of fractionated plasma separation and adsorption. We studied 17 patients from two centers treated with Prometheus, comparing standard anticoagulation with heparin (15 treatments) and a combination of heparin and the synthetic prostacyclin epoprostenol (22 treatments). Standard coagulation tests, proteins C and S, and thrombin-antithrombin (TAT) complex were determined, and adverse events were recorded. All but two treatments could be completed as scheduled, although filter exchange due to filter clotting was required in 24% of the treatments. Three out of 17 patients developed severe bleeding complications within 24 h of treatment. There were no overt thrombotic events. Addition of epoprostenol neither reduced coagulation-related adverse events nor improved standard coagulation parameters. Protein C, but not protein S, showed a significant reduction (23 +/- 18%) after Prometheus treatments, but levels rebounded to baseline within 18 h. TAT levels--a measure for activation of coagulation--were only altered by Prometheus in patients where TAT was already elevated before treatment. In conclusion, anticoagulation of Prometheus with heparin is feasible but still associated with a relatively high frequency of filter clotting and a considerable risk of severe bleeding in this high-risk patient population. As addition of epoprostenol did not prove beneficial, other strategies, such as regional anticoagulation with citrate, should be further evaluated.