7 sessions of on-line HDF. Furthermore, consciousness remained clear after initial improvement by ALS with on-line HDF over a period of 16.4 ± 3.4 days until discontinuation of treatment. Unusual accumulation of agents acting on the central nervous system requiring the liver to deal with toxic substances was the main mechanism of consciousness disorder caused by liver CO1686 failure [17]. Ammonia, a key toxin in these substances [18], is related to brain edema Inhibitors,research,lifescience,medical and may lead to cerebral herniation, which is a major cause of death in patients with acute liver failure. An arterial blood ammonia concentration above 200 μg/dL conferred a high

risk of cerebral herniation [19]. On the other hand, Inhibitors,research,lifescience,medical our experience is that serum ammonia concentration does not correlate with the degree of hepatic encephalopathy in patients with acute liver failure occasionally. It was shown that HD was insufficient for the treatment of hepatic encephalopathy [20], although it could remove ammonia, a small molecule [21-23]. At present, it is proposed Inhibitors,research,lifescience,medical as one

opinion that the causal agents of hepatic encephalopathy are presumed to be middle molecules [24]. Blood purification therapy for patients with acute liver failure aims to remove ammonia, which can cause a critical situation with brain edema, and middle molecules have a high potential for central nervous system toxicity. Splendiani et al. [20] reported improvement of consciousness in 37.5% of patients with acute liver Inhibitors,research,lifescience,medical failure who were treated with plasmapheresis. Therefore, plasma exchange alone is clearly insufficient for maintaining alert wakefulness in patients with severe hepatic encephalopathy. Improvement of consciousness

in patients with hepatic encephalopathy was reported in 40% of those treated with HD and 78% of those receiving hemofiltration (HF) [20]. HD is effective in removing substances of small molecular weight but cannot provide efficient removal of substances of middle molecular weight. HF is effective in removing middle molecular weight substances but cannot remove small molecules effectively [25]. To compensate for these disadvantages, HDF Inhibitors,research,lifescience,medical is widely acknowledged today as a means of removing both small and middle molecular weight substances in renal replacement therapy [26-28]. In HDF, there are costs and storage problems because Bay 11-7085 of the large amount of sterile substitution fluid required, which is usually supplied in ready-to-use bags. Furthermore, there is the need to connect multiple bags and tubing segments, the circuit is relatively complicated, and the risk of blood contamination may be high. For these reasons, HDF has not been applied routinely in the treatment of chronic renal failure, and is not commonly available in general facilities for the treatment of acute liver failure. The new technique of on-line HDF is superior to conventional HDF and reduces the cost and simplifies the procedure [5].