严重肝病时肝细胞不能清除体内血液中的有毒物质;出现广泛的门-腔侧枝循环或在门-腔静脉分流术之后,来自肠道的有毒物质绕过肝脏而进入体循环。以上情况均可导致人体严重代谢紊乱,并致中枢神经系统受损而引起以意识改变和昏迷为主的一系列精神神经症状,称为肝性昏迷,或称肝性脑病。肝性昏迷除发生在急性重症肝炎患者外,大多是一个逐渐发展的过程。其发病机理目前倾向于各种因素的综合作用,首先是氨代谢紊乱所致的氨中毒。这是由于肝病时肝脏不能将肠道内形成的氨(外源性氨)和肾脏、肌肉产生的血氨(内源性氨)合成为无毒的尿素或由于门腔静脉间的交通,使从肠道进入门静脉的氨未经肝脏代谢直接进入体循环所致。其次即所谓假性神经介质学说,认为在肝功能衰竭时,体内某些芳 Hepatic cells in severe liver disease can not purge the body of toxic substances in the blood; a wide range of portal-cavity collateral circulation or portal-vena cava shunt, the toxic substances from the intestine bypass the liver and enter the systemic circulation. These conditions can lead to severe metabolic disorders in the human body and lead to a series of neurotic symptoms, such as hepatic coma, or hepatic encephalopathy, caused by the change of consciousness and coma. In addition to the occurrence of hepatic coma in patients with acute severe hepatitis, mostly a gradual process. Its pathogenesis now tends to the combined effect of various factors, the first is caused by ammonia metabolism disorders caused by ammonia poisoning. This is because the liver can not synthesize ammonia (exogenous ammonia) formed in the intestine and blood ammonia (endogenous ammonia) produced by the kidneys and muscles into non-toxic urea due to liver disease or due to traffic between the portal venules Intestinal enter the portal vein of ammonia without liver metabolism directly into the systemic circulation. Second, the so-called pseudo-neurotransmitter theory, that in the liver failure, some of the body Fang