Plasma lipid levels in preterm neonates receiving parenteral fat emulsions

Concentrations of various plasma lipid fractions were determined during 96 hours of continuous parenteral infusions of lipid emulsions in 10 normally-grown neonates whose birth-weights ranged from 960 to 1760 g and whose gestational ages ranged from 26 to 32 weeks. Total lipid, triglyceride, free glycerol, and free fatty acid concentrations were measured. During lipid infusions, mean plasma concentrations of all lipid fractions increased above the mean preinfusion values if 2 g/kg a day or more of lipid emulsion was used. There were no further significant increases in mean plasma lipid levels if the infused dosage was increased to 3 or 4 g/kg a day. At these higher infusion rates however, there were considerable individual variations. The only neonate less than 27 weeks of gestation had plasma lipid levels severalfold higher than any of his peers, his plasma was frankly creamy on visual inspection, and the study had to be stopped. Further investigations are needed to determine the optimal modalities of parenteral nutrition with fat emulsions.