Energy metabolism, substrate utilization, metabolite and hormone levels in infants fed various parenteral solutions

Previous observations on the effects of various types of parenteral nutrition on changes in oxygen consumption, respiratory quotient, total heat production, distribution of nutrient utilization, metabolic and hormonal levels in infants during the neonatal and postneonatal periods are reviewed. The relevant findings obtained in fifty-two newborn infants infused with different types of metabolic solutions were as follows. Oxygen consumption increased during Aminosol-glucose and Intralipid-glucose infusion. The respiratory quotient varied according to the oxidation of the nutrients. A significant elevation was observed during Aminosol-glucose infusion, which tended to fall in response to Intralipid. Total heat production was increased during all types of parenteral nutrition, and substrate utilization depended on the quality and amount of nutrient intake. The magnitude of the changes in concentrations of metabolites (glucose, free fatty acids, alpha-amino-nitrogen) and insulin and growth hormone were smallest when the parenteral nutrition consisted of glucose, amino acids and lipid and the total caloric intake did not exceed the maintenance energy expenditure. On the basis of the results, during the neonatal period it seems advisable to administer as parenteral nutrition, about 70--75 kcal/kg/day in the form of 7.0--8.0 g/kg/day glucose, 1.7--2.0 g/kg/day amino acids and 3.0--4.0 g/kg/day lipid.