Enteral and parenteral branched chain amino acid-supplemented nutritional support in patients with encephalopathy due to alcoholic liver disease

Abstract

The effects of branched chain amino acid (BCAA)-enriched diets (fed for 7 days) on encephalopathy, plasma amino acid concentrations, aromatic amino acid turnover, and protein synthesis rates were determined in eight patients with alcoholic liver failure. Four patients were given the diet intravenously (iv group) (total amino acids, 60-80 g/day, BCAA content 51%, energy 2000 kcal/day) and four patients (NG group) were given a semi-elemental formulation via constant nasogastric (NG) infusion (amino acids 58 g, BCAA 43%, oligopeptides 19.5 g, energy 2000 kcal/day). The enteral diet was given at one-half strength for the first 3 days. A 10-hr constant infusion of [U-14C]phenylalanine tracer was used in four patients to measure aromatic amino acid (AA) turnover and rates of incorporation into various body proteins. Seven of the eight patients made a good clinical recovery, with reversal of encephalopathy within 3 days of dietary intervention. One became septicemic and deteriorated. While plasma bilirubin concentrations dropped, liver enzymes remained elevated. Mean nitrogen balance was negative at the beginning and positive at the end of the study, in both groups. Initial amino acid profiles demonstrated low plasma BCAA content and BCAA:AA ratios. Significant improvements occurred in the iv group by day 2 and in both groups by day 7. Isotope studies showed that, whereas aromatic amino acid oxidation remained unchanged, greater quantities were incorporated in whole body protein, albumin, transferrin, fibrinogen, and immunoglobulins.