Regional anticoagulation and antiaggregation for CVVH in critically ill patients: a prospective, randomized, controlled pilot study

Background: The aim of this study is to assess the efficacy and clinical safety of regional anticoagulation (heparin pre‐filter plus post‐filter protamine) plus antiaggregation (pre‐filter prostacyclin) [Group 1 (G1)] vs. only systemic heparin anticoagulation without antiaggregation [Group 2 (G2)] in critically ill patients with acute renal failure undergoing continuous veno‐venous haemofiltration (CVVH). Methods: One hundred and ten patients were randomized in a prospective, controlled pilot study. G1 patients received 1000 U/h pre‐filter heparin, 10 mg/h post‐filter protamine sulphate and 4 ng/kg/min pre‐filter prostacyclin, while G2 patients received 1000 U/h pre‐filter heparin. The haemofilter transmembrane pressure (TMP) and lifespan, as well as the platelet count were observed 1 h before, and at 6, 12, 18, 24 and 36 h from the beginning of CVVH. Results: Haemofilter TMP remained unchanged in G1 while it increased up to three times in G2 (P=0.0002). The median filter lifespan was 68 h in G1 and 19 h in G2. The rate of spontaneous circuit failure was 24% in G1 and 93% in G2 (P=0.0001). The platelet count was stable over the treatment period in G1 while in G2 it decreased progressively (P=0.0073). Conclusion: In critically ill patients suffering from acute renal failure, regional anticoagulation with pre‐filter heparin and post‐filter protamine plus antiaggregation during CVVH is a simple and safe procedure that prevents increases in filter TMP and increases circuit life time compared with systemic anticoagulation with pre‐filter heparin only.