In addition to what alchemist stated earlier, below are my thoughts:
In neonatal parenteral nutrition, lipids are not allowed to exceed 60% of total caloric intake due to potential complications/risks:
o Potential risk of kernicterus at low levels of unconjugated bilirubin because of displacement of bilirubin from albumin binding sites by free fatty acids. As a general rule, do not advance lipids beyond 0.5 g/kg/d until bilirubin is below threshold for phototherapy.
o Potential increased risk or exacerbation of chronic lung disease.
o Potential exacerbation of Persistent Pulmonary Hypertension (PPHN).
o Lipid overload syndrome with coagulopathy and liver failure.
Please keep in mind that very preterm infants may not tolerate that much dextrose and may even need insulin as an infusion to achieve adequate caloric intake without hyperglycemia.
Potential complications/risks of carbohydrate include:
o Hyperglycemia or hypoglycemia.
o Glycosuria and potential osmotic diuresis.
o Cholestasis and/or hepatic steatosis with high caloric intake usually from long-term high concentration infusion.