Parenteral nutrition (PN) is the IV infusion of nutrients for the purpose of tissue maintenance, metabolic requirements and growth promotion in babies unable to tolerate full enteral feeds 

• Newborn babies – commence PN if:
  
  • <31⁺⁰ weeks’ gestation
  • ≥31⁺⁰ weeks’ gestation – if sufficient progress not made with enteral feeding in first 72 hr after birth
  • unlikely to establish sufficient enteral feeding, e.g. babies with congenital gut disorder or critical illness (e.g. sepsis)
• Babies who have previously established some enteral feeds, commence PN if:
  
  • enteral feeds stopped and unlikely to be restarted within 48 hr
  • enteral feeds stopped for >24 hr and unlikely to be sufficient progress with enteral feeding within further 48 hr
• Commence PN as soon as decision made baby meets criteria (within 8 hr of decision at latest)

• Administer PN continuously over 24 hr

Peripheral PN

• PN should be ideally delivered centrally (high glucose and electrolyte concentrations result in a high osmolarity – limiting nutrition given peripherally)
• Depending on aqueous feed e.g. Vamin® composition, local policy may permit peripheral administration of certain products in certain circumstances – check local policy before prescribing
• Running lipid peripherally in addition to aqueous phase may prolong the life of the peripheral cannula

Central PN

• Requires placement of a central catheter [see Long line insertion (peripherally sited) guideline] with tip in either superior vena cava or inferior vena cava
• Infuse PN via a dedicated lumen
  
  • continuous vancomycin/sodium/potassium chloride infusion may be administered simultaneously with PN, providing maximum total concentration ≤200 mmol/L 
• If access difficult, discuss PN drug compatibilities with pharmacist 
• Shield syringes, bags and infusion sets from light

• For practical and safety reasons standard bags are preferred as neonatal nutritional requirements are largely predictable (see Nutrition and enteral feeding guideline)

• If required, additional electrolytes can be infused alongside PN (see Central PN)

Volume

• PN provided primarily for nutrition
  
  • although fluid and nutrition are closely linked and volume needs to be considered carefully, the concepts are not interchangeable e.g. providing 150 mL/kg/day fluid does not guarantee provision of adequate nutrition
  • may be beneficial to give concentrated aqueous phase solutions to enable administration of additional drugs without compromising nutritional intake
• 30–40 mL/kg/day feed to be established before commencing weaning of PN

Protein/amino acid

• Initial PN bag to contain 1.5–2 g/kg/day 
• Target protein intake, by day 5 of life, (regardless when PN was commenced): 
  
  • preterm babies: 3–4 g/kg/day 
  • term babies: 3 g/kg/day
• Administer sufficient carbohydrate to facilitate the accretion of protein (approximately 25 kcal/g protein)

Glucose

• 6–9 g/kg/day in first 24 hr – take PN and additional fluids into consideration

• Increase glucose intake as tolerated to optimise calorie intake to maximum of 9–16 g/kg/day

• If severe or persistent hyperglycaemia develops, commence insulin infusion – see Administration of Actrapid® insulin (soluble insulin) in Hyperglycaemia guideline

   

Electrolytes

• Sodium: ≥3 mmol/kg/day in preterm babies who have commenced natriuresis
• Potassium: ≥2 mmol/kg/day from day 2–3 
• Babies given electrolytes solely as chloride salts can develop hyperchloraemic metabolic acidosis (consider adding acetate to PN, where available)
• Monitor serum phosphate twice weekly; aim to maintain at around 2 mmol/L

Micronutrients

• Calcium: 0.8–1 mmol/kg/day first 48 hr of life, increased to 2 mmol/kg/day thereafter
• Phosphate: 1 mmol/kg/day first 48 hr of life, increased to 2 mmol/kg/day 
  
  • monitor phosphate – higher doses may be required
  • if possible, use organic phosphate compounds
• Magnesium: 0.18–0.2 mmol/L 

Trace elements

[/heading3]Peditrace®[/heading3]

• Addition of trace element admixture (Peditrace®) shortens the shelf-life of standard bags  to 7 days

• Zinc and selenium will be contained within standard aqueous feed bags

• If baby on short-term PN and receiving some milk feeds, trace elements may not be required

• If baby on PN >2 weeks with enteral feed intake of <50% and not receiving Peditrace®, discuss with PN pharmacist/dietitian 

Fat

• 2 lipid emulsions used routinely on NNU: Intralipid® (soya bean origin) and SMOF lipid (blend of soya bean, MCT fat, olive oil and fish oils)
• Consider SMOF lipid for babies with conjugated bilirubin >50
• Commence lipid 1–2 g/kg/day IV when commencing aqueous phase
  
  • increase by 0.5–1 g/kg/day to maximum 3–4 g/kg/day
  • all lipid to be infused over 24 hr

Vitamins

• Vitlipid (fat soluble vits) + Solivito (water soluble vits) are added to lipid syringes (Lipid bags do not contain vitamins)
  Should be given within 48 hr of starting PN

Catheter-related: [see Long line insertion (peripherally sited) guideline]

• Peripheral catheters: extravasations and skin sloughs
• Septicaemia

Electrolyte abnormalities

• Electrolyte and acid-base disturbances 

Metabolic

• Hyper/hypoglycaemia, osmotic diuresis 
• Metabolic bone disease: mineral abnormalities (Ca/PO₄/Mg) 
• Hyperlipidaemia and hypercholesterolaemia
• Conjugated hyperbilirubinaemia

PN-associated cholestatic hepatitis (see Liver dysfunction in preterm babies guideline)

• Can occur with prolonged PN (>10–14 days)
  
  • probably due to combination of PN hepato-toxicity, sepsis and reduced oral feeding
  • often transient
  • usually manifests as rising serum bilirubin (with increased conjugated component >50 micromol/L) and mildly elevated transaminases
  • leads to deficiencies of fatty acids and trace minerals in enterally fed babies
  • even small enteral feeds will limit or prevent this problem and therefore trophic feeds (10–20 ml/kg/day) should be given to all babies on PN unless there are contraindications such as acute clinical instability or NEC 
  • consider other causes of hyperbilirubinaemia (PN-induced cholestasis is diagnosis of exclusion) e.g. CMV, hypothyroidism
  • if failure to progress with enteral feeding in a timely fashion, seek advice from unit nutrition team, neonatal dietitian or paediatric gastroenterologist

• Commence enteral feeds as soon as possible
  
  • see Nutrition and enteral feeding guideline for initiating and advancing enteral feeds 
• Do not wean PN until total volume of 180 mL/kg/day reached (unless fluid restricted) i.e. this includes >30 mL/kg/day enteral feed
• When advancing enteral feedings, proportionally reduce rate of PN administration to achieve desired total fluid volume
• When weaning PN decrease aqueous and lipid simultaneously in proportion to ensure correct ratio of calorie distribution by fat and carbohydrate
• Ratio dependent on total volume of aqueous phase + lipid, e.g. if increasing feed by 1 mL, decrease aqueous phase by 1 x (aqueous phase mL/hr/aqueous phase mL/hr + lipid mL/hr), and decrease lipid by 1 x (lipid mL/hr/aqueous phase mL/hr + lipid mL)
• Assess nutrient intake from both PN and enteral feed in relation to overall nutrition goals
• If enteral vitamins required, commence when lipid syringe infusion <10 mL/kg/day
• For babies born <28 weeks, stop PN within 24 hr of tolerating 140–150 mL/kg/day of enteral feeds and fortify the milk if appropriate (see Nutrition and enteral feeding guideline)
• For babies born ≥28 weeks, stop PN within 24 hr of tolerating 120–140 mL/kg/day of enteral feeds and consider fortification if appropriate (see Nutrition and enteral feeding guideline)