Metabolic effects of septicaemia in newborn and young infants with particular reference to the plasma free amino acids.

Blood samples were obtained from 13 infants with clinically and microbiologically confirmed septicaemia. Two subgroups of the septic infants were formed according to postnatal age, an early onset group consisting of 6 infants younger than 7 days, and a late onset group comprising 7 infants of 20 infants. The blood samples were analysed for 18 plasma amino acids and glucose, lactate and FFA. Except the significantly lowered blood glucose in the early onset group of infants, no appreciable change occurred in the glucose, lactate and FFA levels. The plasma aminogram was different in the two groups, as hypoaminoacidaemia was more pronounced in the early onset group. The branched chain amino acids decreased significantly in both groups. The three important glucogenic amino acids alanine, glycine and proline showed a decrease only in the early onset group. Among the calculated plasma amino acid ratios the phenylalanine: tyrosine quotient was markedly increased. This, in addition to the response of the branched chain amino acids, has been found characteristic of a variety of clinical and experimental infections.