The effect of solutions of varying branched-chain concentration on the plasma amino acid pattern and metabolism in intensive care patients

Abstract

30 intensive care surgical patients were investigated over a period of five days following trauma or major surgery. They were randomised by card into two groups, Group I received an amino acid solution containing 45 per cent branched-chain amino acids (BCAA), and group II an amino acid solution with a 10 per cent content of BCAAs. After 24 hours of infusion, the total amino acid concentration and branched-chain amino acid concentration in the plasma of Group I patients already clearly exceeded the normal range, and continued to increase during the period of study. In Group II these parameters rapidly returned to normal where they remained. Cumulative negative nitrogen balance and nitrogen excretion on each day of investigation were significantly less in Group II. These results indicate that after severe trauma or major surgery amino acid solutions containing high concentrations of BCAAs may be an unphysiological load on the already stressed metabolism, rather than a benefit.