The importance of the highest normokalemia in the treatment of early hepatic encephalopathy.

An inverse relation is known to link blood potassium with renal synthesis and the release of ammonia. Given the liability of hyperammonemia for precipitating hepatic encephalopathy (HE), 28 patients affected by stage I HE were equally divided into two groups and maintained up to their death at the highest (5.4-5.5 mEq/l) or the lowest (3.5-3.6 mEq/l) normokalemia levels. When compared with the lowest normokalemia group, the highest one showed an early, albeit transient, improvement in the mental state (as assessed by both EEG and psychiatric investigations) and to a lesser extent in hepatic functions (as assessed by the variations in serum bilirubin, GPT, GGT and plasma prothrombin time). In the highest normokalemia group the survival was also prolonged. The cause of this improvement may be related to the induced decrease in blood pH, the consequent depression of renal ammoniagenesis and the rise in the arterial and urine NH+4/NH3 ratios. These factors reduce the entry of ammonia into the cells and enhance the urinary excretion of this metabolite, respectively.