Background
Parenteral nutrition is central to the care of very immature infants. Current international recommendations favour higher amino-acid intakes and fish oil-containing lipid emulsions.
Objective
The aim of this two-by-two factorial, double-blind multicentre randomised controlled trial was to compare the effect of high (immediate Recommended Daily Intake: Imm-RDI) versus low (incremental introduction: Inc-AA) parenteral amino-acid delivery, commenced within 24 hours of birth, on body composition, and a multi-component lipid emulsion containing 30% soy bean oil, 30% medium chain triglycerides, 25% olive oil and 15% fish oil (SMOF) versus soybean oil based lipid emulsion (SO) on Intra-Hepato-Cellular Lipid (IHCL) content.
Results
We randomised 168 infants born <31 weeks gestation. We evaluated outcomes at term in 133 infants. There were no significant differences between Imm-RDI and Inc-AA groups for non-adipose mass (adjusted mean difference (95% CI): 1.0g (-108, 111) p=0.98) or between SMOF and SO groups for IHCL (adjusted mean ratio SMOF:SO (95% CI): 1.1 (0.8, 1.6) p=0.58). SMOF does not affect IHCL content. There was a significant interaction (p=0.05) between the two interventions for non-adipose mass. There were no significant interactions between group differences for either primary outcome measure after adjusting for additional confounders. Imm-RDI infants were more likely than Inc-AA infants to have blood urea nitrogen levels greater than 7mmol/l or 10mmol/l respectively (75% vs 49%; p<0.01 and 49% vs 18%; p<0.01). Head circumference at term was smaller in the Imm-RDI group (mean difference (95% CI): -0.8cm (-1.5, -0.1) p= 0.02). There were no significant differences in any pre-specified secondary outcomes including adiposity, liver function tests, incidence of conjugated hyperbilirubinaemia, weight, length, mortality and brain volumes.
Conclusions
Immediate delivery of Recommended Daily Intake of parenteral amino-acids does not benefit body composition or growth to term and may be harmful.