Early or delayed parenteral nutrition for infants: what evidence is available?

PURPOSE OF REVIEW: To review the current evidence evaluating early versus delayed commencement of parenteral nutrition in infants. RECENT FINDINGS: Recent studies in very premature infants (<32 weeks gestation) have shown that early commencement of parenteral nutrition immediately after birth improves physical growth. However, there are concerns that early use of very high dose of amino-acids (>3.5 g/kg/day immediately after birth) may cause metabolic acidosis, elevated blood urea, slower head growth and refeeding-hypophosphatemia syndrome. A recent multicentre randomized controlled trial found that commencement of parenteral nutrition within 24-h of admission increases the risk of infections and prolongs the duration of ventilation and ICU stay in full-term neonates, older infants and children. The study also found that delaying to day 8 of admission increased the risk of hypoglycaemia. SUMMARY: Benefits of commencing parenteral nutrition on the first day of life appear to outweigh risks in very premature infants; however, it is prudent to avoid early very high doses of amino acids (>3.5 g/kg/day) in the first few days of life. In moderate to late preterm infants, if enteral feeds are not tolerated by 72 h, it is reasonable to commence parenteral nutrition. In full-term and older infants, it is preferable to avoid parenteral nutrition within 24 h of admission and consider delaying by further few days. Diligent monitoring of blood glucose, serum phosphate and other parameters is essential while on parenteral nutrition.