Prospective study on the efficacy of branched-chain amino acids in septic patients

The metabolic response to sepsis is characterized by increased proteolysis and gluconeogenesis, reduced protein synthesis, and negative nitrogen balance. The effects of a solution with a high proportion of branched-chain amino acids (BCAA) on the nutritional state of septic patients were evaluated. Eighty patients with peritonitis were divided into two groups of 40 patients; group 1 was administered a solution with 22.5% BCAA and group 2 with 45% BCAA. The following parameters were evaluated: anthropometrics, creatinine/height index, urinary 3-methylhistidine, nitrogen balance, stress index, albumin, prealbumin, transferrin, retinol binding protein, lymphocytes, delayed cutaneous sensitivity tests, studies of hepatic function, and plasma aminogram. In group 2 a more positive nitrogen balance, a greater drop in the stress index, a rise in plasma prealbumin and retinol binding protein levels, an increase in the creatinine/height index, and a more marked fall in the urinary excretion of 3-methylhistidine were found. When solutions with a high BCAA content were administered, there was an increase in the plasma concentrations of these amino acids in the BCAA/aromatic amino acid quotient and a decrease in the aromatic amino acids. Plasma concentrations of leucine and valine achieved very high, potentially toxic, levels at 15 days when solutions with high BCAA content were used. It is concluded that solutions with BCAA are advisable for use in the septic patient in the increased protein catabolic phase, where positive nitrogen balance, a reduction in muscle protein catabolism, and faster recovery of muscle and visceral protein were obtained.