High lipid parenteral nutrition improves portasystemic encephalopathy

We have conducted a randomized double crossover study over 4 days in six parenterally fed patients with portasystemic encephalopathy (PSE) in which the nonprotein energy source of otherwise identical feeds was alternately all glucose or predominantly fat. Concentrations of plasma branched chain amino acids (BCAA), plasma insulin, and blood glucose were measured after an initial fast and subsequently after each of the four 24-hr periods of isonitrogenous feeding. The grade of PSE was assessed clinically and by the number connection test, BCAA concentrations were significantly lower during the glucose infusion than during fasting or the lipid infusion. PSE was significantly less with the lipid than with the glucose infusion. Trials testing the effect of infused BCAA must take account of the opposing effect on BCAA concentrations of simultaneous glucose infusion. A high lipid feed may have advantages in the short-term treatment of PSE.