Anticoagulation with prostacyclin and heparin during continuous venovenous hemofiltration

OBJECTIVES: To investigate anticoagulation with prostacyclin (prostaglandin I2 PGI2) and/or heparin during continuous venovenous hemofiltration, and the role of in vitro tests of primary hemostasis in controlling anticoagulation. DESIGN: Prospective, randomized, controlled trial. SETTING: Intensive care unit. PATIENTS: Forty-six consecutive, critically ill, mechanically ventilated patients with postoperative acute renal failure. INTERVENTIONS: Anticoagulation of the patient's blood was accomplished using heparin (6.0 +/- 0.3 IU/kg/hr for group 1), PGI2 (7.7 +/- 0.7 ng/kg/min for group 2), or both PGI2 and heparin (6.4 +/- 0.3 ng/kg/min, 5.0 +/- 0.4 IU/kg/hr, respectively, for group 3), administered into the extracorporeal line before the hemofilter during continuous venovenous hemofiltration. MEASUREMENTS AND MAIN RESULTS: After Ethics Committee approval and informed consent were obtained, tests of primary and secondary hemostasis, plasma concentrations of 6-ketoprostaglandin F1 alpha (by radioimmunoassay), and hemodynamic measurements were performed before hemofiltration and 24 hrs after hemofiltration. In groups 1 and 3, hemodynamic parameters remained stable, whereas in group 2 (the PGI2 group), there were significant reductions in systemic and pulmonary vascular resistances and mean arterial pressure. Platelet function was unchanged in group 1, and was inhibited in groups 2 and 3. Corresponding with the prolongation of in vitro bleeding time, the 6-ketoprostaglandin F1 alpha concentration was increased, indicating an effective inhibition of platelet aggregation within the hemofilter. Platelet counts remained stable in all patients. Plasma coagulation tests were stable in groups 2 and 3, and were prolonged in group 1. In all patients, no major bleeding complications were observed and there was no clinically important bleeding. Mean hemofilter duration lasted longest in group 3. Blood urea nitrogen and circulating creatinine concentrations decreased significantly in groups 2 and 3 within the study period. CONCLUSIONS: Patients receiving both PGI2 and heparin showed better hemodynamic profiles and enhanced hemofilter duration compared with the other groups and no bleeding complications were observed. Therefore, we recommend anticoagulation with PGI2 and heparin during continuous venovenous hemofiltration with close monitoring of platelet function, coagulation profile, and overall hemodynamics.