Evaluation of different nitrogen sources in high-calorie parenteral therapy

Abstract

Five infants and two children who required prolonged high-calorie parenteral therapy were placed on nitrogen-balance studies while receiving alternate courses of two nitrogen sources; i.e., a casein hydrolysate and a synthetic amino acid solution. Quantitative analyses of plasma and urine amino acid levels were carried out during the administration of both solutions. Administration of either synthetic amino acid or casein hydrolysate solutions in concentrations of 2.125% and 4.25% resulted in positive nitrogen balance and consistent apparently equal weight gain in both concentrations. The infusion of 6.7% synthetic amino acid solutions, in conjunction with a somewhat lower caloric intake than previously employed, resulted in a more positive nitrogen balance but a diminished rate of weight gain. Methionine was the only plasma amino acid component that was consistently elevated during these infusions. The solution of 2.125% synthetic amino acids produced the same rate of weight gain as the other solutions studied, with a constant significant positive nitrogen balance. When this nitrogen source is employed, potential complications in therapy appear to be minimal.