Plasma amino acids in supplementary parenteral nutrition of preterm infants. Effect of different quantities of amino acid infusion and comparison with enteral feeding.

The present investigation aims to determine quantity and quality of the amino acid (AA) solution to be used in supplementary parenteral nutrition (SPN). We established the plasma AA concentrations of preterm infants (birthweight 1160-1940 g, mean 1540; gestational age 29-30 weeks, mean 32) divided into three groups. Group I (n = 11) and group II (n = 12) were put on a standardised SPN regimen starting with an intravenous supply of 2.5 resp. 1.5 g AA/kg/day. Infants of group III were formula-fed, and served as controls. A total of 231 aminograms was obtained during the first two weeks of age. Comparison of groups I and II to group III revealed plasma accumulation of six AA in group I. Supplementation in group II resulted in a normal pattern, except alanine, proline, and methionine. However, only deviations of proline and methionine may be judged as imbalances, and lowering in composition may be considered. We conclude that the low intravenous AA intake employed in group II may be preferred in SPN of preterm infants.