Nitrogen balance in adult hospitalized patients with the use of a pediatric amino acid model.

Normalization of plasma amino acid patterns and that relationship to improved nitrogen balance was studied using a pediatric-specific amino acid solution in 21 adults requiring total parenteral nutrition therapy. There was a significantly positive correlation between improved nitrogen balance and the amino acids cystine, tyrosine, total cysteine/cystine, and ornithine. When additional cysteine was added to the solution of 11 subjects, taurine also correlated with nitrogen balance. Despite higher amounts of histidine in solution, plasma amino acid levels were not normalized. These amino acids, heretofore considered nonessential, may be required in specific molar ratios in stress. The use of a 30% branched-chain pediatric-balanced amino acid solution resulted in near normalization of plasma amino acid levels and group mean positive nitrogen balance.