Parenteral nutrition in neonates — formative SAQs

SAQ 1 (10)

A 780 g infant is born at 26 weeks' gestation. A umbilical venous catheter is sited at one hour of life and the team asks you to prescribe the parenteral nutrition for the first day. ^{[2] [6]}

1. Explain why the very preterm infant needs early aggressive parenteral nutrition. (3) ^[2]
2. State the day-one starting doses and the ESPGHAN advancement targets for amino acids, glucose (as a glucose infusion rate) and lipid. (4) ^[6]
3. Outline the daily monitoring schedule and the four complications you actively prevent. (3) ^[4]

Model answer

1. Most glycogen, fat and protein stores are deposited in the third trimester the infant never completed, so the very preterm carries the smallest reserve at the moment of highest metabolic demand; the fetal protein accretion rate is 3.5 to 4 g/kg/day, the most anabolic period of life. Withholding nutrition flips this anabolic state into negative nitrogen balance within hours, with loss of brain and somatic growth that does not fully recover, so early amino acids directly after birth are a developmental necessity. ^[2]
2. Day one starts amino acids at 1.5 to 2 g/kg/day, a glucose infusion rate of 4 to 6 mg/kg/min, and lipid at 1 to 2 g/kg/day. Advance over the first days to the ESPGHAN targets of amino acids 3 to 3.5 g/kg/day, glucose infusion rate 10 to 12 mg/kg/min, and lipid 3 to 3.5 g/kg/day, with energy around 110 to 135 kcal/kg/day. ^[6]
3. Daily monitoring covers glucose each shift, daily weight on a gestation-specific chart, the electrolyte and metabolic panel (sodium, potassium, chloride, bicarbonate, calcium, phosphate, magnesium), triglycerides when advancing lipid, and liver function from the second week. The four complications to prevent are catheter-related bloodstream infection, PN-associated cholestasis (IFALD), metabolic derangement (hyperglycaemia and lipid intolerance), and refeeding syndrome. ^[4]