Orthotopic liver transplantation (OLT) often involves large blood loss and replacement, as well as administration of large amounts of blood products to correct coagulation defects. Renal free water excretion is often impaired in end-stage liver disease and not responsive to routine diuretic therapy, predisposing these patients to accumulation of extravascular lung water. The effects of the intraoperative use of continuous arteriovenous hemofiltration (CAVH) on cardiopulmonary and oxygen transport variables were studied in ten patients during and 24 hours after OLT. CAVH prevented increases in pulmonary shunt fraction while decreasing PEEP and FIO2 requirements. Pulmonary compliance was significantly higher after operation in patients receiving CAVH. Before surgical dissection, hemodynamic effects of CAVH were minimal. Postoperatively, patients having CAVH had lower cardiac filling pressures and more normal systemic vascular resistance than did patients not having CAVH. These data suggest that CAVH may be a useful intraoperative technique for patients with impaired renal function undergoing liver transplantation.