The Effect of Parenteral Lipid Emulsions on Pulmonary Hemodynamics and Eicosanoid Metabolites in Preterm Infants: A Pilot Study

Background: Soy-based intravenous fat emulsion (IVFE) is known to cause a rise in pulmonary artery pressure in the preterm infant, thought to be mediated through eicosanoid metabolites of linoleic acid. We compared the effect of soy-based IVFE and an olive-oil-based IVFE containing less than half the content of linoleic acid on pulmonary artery pressure and eicosanoid metabolites in preterm infants receiving parenteral nutrition. Methods: In this pilot study at a regional neonatal intensive care unit (ICU), infants received either a soy-based or olive-oil-based IVFE as part of an otherwise identical feeding protocol. Pulmonary artery pressure and urinary thromboxane B2 and prostaglandin F1 alpha were measured at baseline and maximum lipid infusion. Results: There was a greater fall in pulmonary artery pressure in the olive-oil-based IVFE group compared with the soy-based IVFE group. A decrease in urine thromboxane/prostaglandin F1 alpha ratio was seen only in the olive-oil-based IVFE group. Conclusions: In the parenterally fed preterm infant, an olive-oil-based IVFE may have a beneficial effect on pulmonary artery pressure when compared with soy-based IVFE. Effects on pulmonary vascular tone are likely to be mediated through alterations in eicosanoid metabolism. A randomized trial is warranted to compare the effects of different lipid emulsions.