Fulminant hepatic failure (FHF) can be described as a potentially fatal condition presenting with hepatic encephalopathy (HE) and coagulopathy associated with acute hepatic dysfunction, regardless of its etiology. Blood purification (BP) is expected to be effective against HE and coagulopathy in FHF. In this paper, we outline the objectives and methods of BP in the treatments of cases with FHF and indicate a concrete method for and outcomes of BP at our facility. In high-flow dialysate continuous hemodiafiltration (HFCHDF), the conventional CHDF bedside console is connected to a personal dialysis console to induce a high flow rate of dialysate. With this method, the dialysate flow rate is about 500 ml/min at maximum, equivalent to about 50 times the dialysate flow rate during ordinary CHDF. The role of plasma exchange (PE) is considered a means of replacing useful substances, such as clotting factors in fresh frozen plasma rather than a means of removing pathogenic substances. As needed, slow PE(SPE) can be incorporated by connection in series. Analysis of data from 90 patients with FHF who underwent BP at our facility after 1990 revealed that restoration of consciousness was achieved in 33(70.2%) of 47 cases when treated with HFCHDF. This survival in the HFCHDF group was significantly higher than that in the CHDF group. Analysis of data from cases in which ammonia could be measured continuously revealed that blood ammonia level decreased over time following HFCHDF. We also revealed that HFCHDF was useful for preventing the side effects of PE, such as hypernatremia, metabolic alkalosis, and sharp decrease in colloid osmotic pressure. It is concluded that HFCHDF is useful in the treatment of HE and for preventing the side effects of PE. Therefore, we suggested that HFCHDF + SPE should be standardized for the treatment of FHF. Copyright (C) 2010 S. Karger AG, Basel