The electrolyte abnormalities which have been described in hepatic failure include a decrease in plasma sodium, chloride, and carbon dioxide content and an elevation of lactic and pyruvic acid.* Elevation of the blood ammonia has also been reported, and, while there seems to be poor correlation between actual blood levels and symptoms of hepatic coma, there is increasing evidence that ammonia plays at least an indirect role in the production of coma.† The studies reported here were carried out in patients with liver coma in an attempt to evaluate these electrolyte alterations and to correlate the clinical symptomatology with alterations in blood ammonia levels. The results of these studies indicate that hepatic coma may in some cases be associated with a respiratory alkalosis, as evidenced by a high blood pH and a low pCO2 level. Although there was poor correlation between blood ammonia levels per se and symptomatology, it