20% solutions of Intralipid® contain 1.2% egg yolk phospholipids and 2.25%
glycerin. The 20% emulsion is preferred for infants because of the lower
proportion of phospholipids relative to calories. The percentages of essential
fatty acids are somewhat variable with linoleic ranging from 44-62% and linolenic
4 - 11%. Meaning that the omega 6 to omega 3 ratios can range from 15:1 to 4:1.
Omegaven® 10% is a fish oil emulsion with an omega 6 to omega 3 ratio of 1:7,
which has been used to treat parenteral nutrition associated liver disease.[ 6 ] This
product is currently not available commercially in the US.
Fat is generally required for skin integrity but especially for brain growth,
development and proper function. The balance of essential fatty acids appears
to be the most important factor to providing healthy lipid nutrition, but patients
can develop essential fatty acid deficiency syndromes. Neonates, especially
premature infants, can develop this problem within a few days of life without the
provision of fatty acids. The syndrome is characterized by dry skin, defective
wound healing and respiratory distress. Provision of 5% - 8% of total calories as
lipid is preventive. As a practical point, each ml of 20% Intralipid® provides 1.1
kcal of linoleic acid. EFA needs in an infant would be met with a dose of 1- 2
ml/kg/day of 20% Intralipid®.
The third macronutrient is protein, which is required for anabolism, growth
and proper immune function. Protein requirements in postoperative or stressed
patients are increased due to accelerated visceral and somatic protein