Early feeding for a preterm baby

Total Parenteral Nutrition (TPN)

• Intravenous nutrition is usually given within the first couple of days when enteral nutrition (by tube) is not possible, for example due to feed intolerance or serious gastrointestinal disease, or while enteral nutrition is being established.  This is known as total parenteral nutrition (TPN) or hyperalimentation
• The nutrients are passed into the bloodstream intravenously; it’s very common to use the umbilical vein of the preterm infant, where a tube is inserted into the umbilicus
• Very low birthweight infants often have relatively delayed gastric emptying and intestinal peristalsis, which means that they can be slow to tolerate enteral feeding via gastric tube-feeds¹
• The ability to provide both total parenteral nutrition and parenteral nutrition over the past four decades has significantly improved the overall survival of newborns when other options of adequate nutritional support were not possible²
• Feeding solutions should be prepared carefully by a specialist pharmacist to minimise the risk of any microbial contamination

Benefits of TPN:

• It provides rapid, maximal nutrition to the preterm infant³
• It minimises tissue catabolism, which helps to achieve an early positive nitrogen balance⁴
• It helps to keep sodium, glucose and acid-base balance stable³

Problems associated with TPN:

• It is associated with hyperbilirubinaemia and hyperglycaemia²
• Because TPN bypasses the regulatory mechanisms that govern nutrient absorbtion, infants can experience vitamin deficiencies or excesses²
• The most common complication is bloodstream infections. However the delivery of a solution via a central venous catheter rather than a peripheral catheter is not associated with a higher risk of infections¹

In the short term TPN is very beneficial for certain preterm infants. However, the overall goal of the nutritional management of a preterm infant is to establish full enteral feedings as soon as possible.

Tube-feeding and minimal enteral feedings

• Preterm infants with a gestational age of greater than 34 weeks are usually able to coordinate sucking, swallowing, and breathing, and so it is safe to establish breast or bottle-feeding.  In less mature infants, oral feeding may not be safe or possible because of neurological immaturity or respiratory compromise¹
• It may be possible to let parents help out with tube-feeding their preterm infant to help with building a bond with their baby and allowing skin-to-skin contact
• Breast milk is the preferred form of feeding for preterm infants.  It is associated with a better tolerance, and provides the infant with additional non-nutritive benefits
• Nutrients are passed into the stomach directly via a fine tube placed via the mouth (oro-gastric feeding), or via the nose (naso-gastric feeding)
• Very small preterm infants cannot tolerate large feeding volumes, so for the first few days they are given small volumes via a tube-feed, usually only about 2-24 ml/kg per day⁵.  These feedings are known as minimal enteral feedings, non-nutritive feeds or trophic feeds
• Tube-feeding is also used for priming the gut for those smallest preterm infants who are getting most of their nutrition from parenteral nutrition¹.Priming means giving small amounts of milk feeds to stimulate the gut
• Minimal enteral nutrition is important to establish as soon as possible as it is associated with the following benefits:
  • Helping to enhance intestinal motility and a reduced whole gut transit time⁶
  • Increased lactase activity and stimulation of the release of gastrointestinal hormones⁷
  • More rapid tolerance of full enteral feeds⁸
  • Improved weight gain ^9,10
  • Reducing the risk associated with a sole use of parenteral nutrition, which can cause a lack of nutrients being present in the gut leading to gut atrophy¹¹