Standardized Parenteral Nutrition for the Transition Phase in Preterm Infants: A Bag That Fits

The optimal composition of standardized parenteral nutrition (SPN) is not yet known, contributing to nutrient deficit accrual and growth failure, with the period of parenteral nutrition weaning, i.e., transition (TN) phase, being identified as particularly vulnerable. We created a comprehensive nutrition database, representative of the nutritional course of a diverse range of preterm infants (n = 59, birth weight 1500 g, gestation < 34 weeks) by collecting hourly macronutrient intake data as part of a prospective, observational study over 19 months. Using a nutrient modeling technique for the TN phase, various amino acid (AA) concentrations of SPN were tested within the database, whilst acknowledging the nutritional contribution from enteral feeds until target AA intakes were consistently achieved. From the modeling, the AA composition of SPN was determined at 3.5 g/100 mL, which was the maximum to avoid exceeding target intakes at any point in the TN phase. However, in order to consistently achieve target AA intakes, additional nutritional strategies were required, which included increasing the exclusion of enteral feeds in fluid and nutrient calculations from <20 mL/kg/day to <40 mL/kg/day, and earlier fortification of breastmilk at 80 mL/kg/day. This data-driven nutrient modeling process supported the development of an improved SPN regimen for our preterm population in the TN phase.