上海交通大学医学院内科学课件 liver cirrhosis.ppt

SURVIVAL TIMES IN CIRRHOSIS STAGES OF HEPATIC ENCEPHALOPATHY NUMBER CONNECTION TEST Slide 346 HEPATIC ENCEPHALOPATHY – NOMENCLATURE Hepatic encephalopathy is subdivided into type A associated with acute liver failure, type B associated with portosystemic bypass without intrinsic hepatocellular disease (portosystemic shunts), and type C when associated with cirrhosis and portosystemic shunting. Ferenci et al., Hepatology 2002; 35:716 Slide 347 CHARACTERISTICS OF TYPE A VS. TYPE C ENCEPHALOPATHY Type A hepatic encephalopathy is of rapid onset, frequently fatal, and related to cerebral edema. Liver transplantation is the most effective treatment. Type C is of gradual onset, rarely fatal, and is caused by porto-systemic shunting. A precipitating cause can often be found and treatment is usually effective. Slide 348 TYPE C HEPATIC ENCEPHALOPATHY IS THE ENCEPHALOPATHY OF CIRRHOSIS In cirrhosis, hepatic encephalopathy results from a combination of portosystemic shunting and failure to metabolize neurotoxic substances. Astrocytes are the only cells in the brain that can metabolize ammonia and, in hepatic encephalopathy, changes in the astrocytes are seen (Alzheimer’s type II astrocytosis). Slide 354 ASTERIXIS IS THE HALLMARK IN THE DIAGNOSIS OF HEPATIC ENCEPHALOPATHY This slide shows typical features of asterixis. Asterixis is best noted with the outstretched arm attempting to dorsiflex the hand with the fingers extended. The initial movement is a “scissors” movement of the fingers. Subsequently, there is a downward drift of the hand with incomplete recovery motion, followed by sudden palmar flexion. The hand then returns to the initial position by dorsiflexion. Slide 41 DIAGNOSTIC ALGORITHM Diagnostic algorithm to investigate the presence of cirrhosis in patients with chronic liver disease. Slide 44 MECHANISMS OF PORTAL HYPERTENSION In fluid mechanics, Ohm’s law states that pressure (P) is dependent upon flow (F) and resistance to flow (R). Therefore, portal