Plasma amino acid changes in the postsurgical newborn during intravenous nutrition with a synthetic amino acid...

Plasma amino acid concentrations during the therapeutic use of a crystalline amino acid solution are presented and discussed. In an attempt to avoid potentially dangerous hyperaminoacidemia, a maximum infusion rate of 350 mg nitrogen/kg/day was chosen. This resulted in the majority of the amino acids remaining within two standard deviations of normal mean,3 although levels of aspartate, glutamate, proline, valine, and isoleucine are in excess of this limit. No amino acid level is as much as one standard deviation below the mean, the lowest in this respect being lysine. A moderate increase in nitrogen provision is probably desirable to improve weight gain, but this solution would result in undesirable increases in these amino acid concentrations.