If 10% of fat is lost before feeding, then 5% of available caloric energy is lost too
About 50% of the energy in human milk is from fat, and this is almost entirely accounted for by the milk triglycerides and their fatty acids. Triglycerides are the major form of fat in the diet and typically provide 98% of the fat in human milk. Only 5% of HBM is fat and fat-soluble components, including many vitamins. The other 95% is water and water soluble components. Each 10% loss of fat during enteral delivery represents a 5% loss of available caloric energy to the NICU infant, because about half of the energy available in HBM comes from the fat. In addition, critical fat-soluble nutrients are not available to the baby if the fat component of HBM is under-delivered.
Clinicians are concerned about nutritional loss during collection, storage, and transfer of HBM. Research has identified systemic losses of fat and lipids during the enteral delivery process. Complex methodologies are required to evaluate the impact of multiple variables on the outcome. In other words, the loss of fats in the HBM delivery model is well documented, but the individual contribution of fat loss for each component in the enteral delivery system has not been adequately studied to date.
How Syringe Choice Can Affect Lipid Delivery
When used with a horizontally oriented pump, off-center syringe tips encourage delivery of lipids first. Centered syringe tips cause lipids to be delivered last. The pump must be tilted or rotated to deliver lipids first with a center-tip syringe, which may void the warranty on the pump.
Rubber Plunger Head
Rubber plunger tips are more conical, creating more surface area for unwanted lipid/fat adhesion to the surfaces of both the plunger piston and the end of the syringe. The solid polypropylene plunger head is flatter, creating less surface area for unwanted lipid/fat adhesion.
Various studies have been done in an effort to quantify the fat (lipid), carbohydrate, and volume loss associated with enteral delivery.
The Netherland study demonstrated loss of 33% triglycerides, 35% lutein, and 26% ß-Carotene in the enteral delivery system. The Netherland study goes further to state that triglyceride loss accounts for 16% of the total caloric intake of neonates. Neither study specifically addresses the impact of oil/lipid soluble micronutrients that are contained in the lost lipids nor the possible NICU impacts of growth and thriving, lung development, eye development, cognitive development, or other physiological attributes. One thing is certain: fat loss reduces nutrient delivery and energy availability.
The importance of human breast milk (HBM) in the development of neonates and infants is well established. Lois Arnold, in Human Milk in the NICU identifies several benefits of human milk for the preterm infant, summarized below:
HBM delivers immunoglobulins, lactoferrin, and lysozyme. It also contains complex carbohydrates such as mucins, oligosaccharides, glycans, and others that prevent bacterial and parasitic adhesion.
HBM coats and protects the gut with high levels of immune proteins and antibodies, contains growth factors to support growth of absorptive cells found in the gut lining, supports gut closure, and reduces permeability to pathogens.
Premature babies can absorb 95% of human milk fat. HBM has the appropriate composition of digestible proteins, as well as supplementary digestive enzymes. HBM contains enzymes that digest fat.