Parenteral Soy Oil and Fish Oil Emulsions: Impact of Dose Restriction on Bile Flow and Brain Size of Parenteral Nutrition-Fed Neonatal Piglets

Background: Parenteral nutrition (PN)-associated liver disease (PNALD) remains a significant cause of morbidity and mortality for neonates dependent on PN. Total fat emulsion dose and composition, particularly the large amount of omega-6 long-chain polyunsaturated fatty acids in plant oils, have been proposed as risk factors for PNALD. We hypothesized restriction of the dose of emulsion would prevent PNALD, regardless of the composition, but growth could be compromised. Methods: Using a neonatal piglet model, we compared conventional soy oil emulsion (Intralipid), dosed high (SO10, n = 8: 10 g/kg/d) and low (SO5, n = 6: 5 g/kg/d), with fish oil (Omegaven), dosed low (FO5, n = 8: 5 g/kg/d). Piglets were given isonitrogenous PN for 14 days. The normal range for all parameters was determined by measurement in equivalent aged sow-reared piglets. Results: Bile flow was lower with high-dose Intralipid, outside the normal range, while higher for the other groups (SO10, 5.4 mu g/g; SO5, 8.6 mu g/g; FO5, 13.4 mu g/g; P = .010; normal range, 6.5-12.2 mu g/g). Total body weight was low in all treatment groups (SO10, 4.4 kg; SO5, 4.5 kg; FO5, 5.0 kg; P = .038; normal range, 5.2-7.3 kg). Brain weight was not different between groups (SO10, 40.3 g; SO5, 36.0 g; FO5, 36.6 g; P = .122; normal range, 41.8-51.4 g). Corrected for body weight, brain weight was lowest in the fish oil group (SO10, 9.3 g/kg; SO5, 8.0 g/kg; FO5, 7.3 g/kg; P < .001; normal range, 5.9-9.0 g/kg). Conclusion: Low-dose fat emulsions reduce the risk of developing PNALD. Further investigation of the risk to brain development in neonates exposed to dose restriction, particularly with fish oil, is required.