Does delaying starting protein benefit late preterm and term surgical newborns?

Abstract

Parenteral nutrition (PN), consisting of carbohydrate, lipid, and amino acid constituent parts, is used in newborns when enteral feeding is insufficient. Those newborns requiring major surgery in the immediate postnatal period, comprising 17% of all late preterm and term newborns admitted to Australian NICUs per annum, are one such group with current supportive management emphasizing the importance of early nutrition. Recent data in children challenges this and suggests potential benefit from delayed provision of amino acids in the acute phase of a critical illness. The PEPaNIC (early vs late parenteral nutrition in the Paediatric ICU) RCT found that delaying PN (specifically amino acids) for a week following PICU admission reduced the length of admission by 30% and duration of ventilation by 40%, effects magnified on post-hoc analysis of the youngest patients. Confirmation of a similar response in ill surgical newborns is needed to drive practice change and improve both short- and longer-term clinical outcomes. Although the exact mechanism(s) remains unclear, the well newborn is exposed to a period of fasting for 48-72 hours following birth before the establishment of maternal milk supply, with fasting also a natural response to illness or surgical stress. Fasting results in up-regulation of autophagy which defines a phenotype of healing and repair, and which critically is suppressed by provision of amino acids. We hypothesize that delayed compared to early provision of the amino acid component of PN in late-preterm and term newborns requiring major surgery in the immediate neonatal period will shorten the duration of neonatal intensive care admission. The aim of this multi-centre, parallel group, superiority, blinded randomised controlled trial is to investigate the impact of delayed provision of the amino acid component of PN (intervention) versus early initiation (standard care) in late-preterm and term newborns requiring major surgery in the immediate newborn period on the duration of neonatal intensive care admission.