Purging the Line: Reducing Fat and Nutrition Loss

 

Delivering Full Human Milk Nutrition in the NICU: Part 2 of 2 (Read part 1)

Human milk is the very best nutrition for all newborn infants, and even more so for very premature and critically ill infants in the neonatal intensive care unit (NICU).

Oftentimes these infants are receiving early nutrition of mother’s own milk or donor human milk through a feeding tube.  Enteral feeding method and rate of delivery varies from gravity, intermittent, and continuous, depending on how well a patient tolerates feeding and individual unit practice. Enteral syringe pumps are used to deliver small amounts of intermittent and continuous feeding, since they allow for a consistent method of delivery over a prescribed amount of time.

Research indicates that human milk feedings administered by tube feedings may decrease fat delivery. Rogers, et al. found the incidence of fat loss increased with longer infusion time.1  Meaning, feeds that are infused slower and over a longer time (often related to infant tolerance) have a higher propensity for greater fat loss. It is of critical importance to have as much fat as possible delivered to the infant because fat equals calories, and these infants require fat for continuous growth and development.

Enteral feeding fat and nutrition loss

What considerations can be made to prevent the loss of fat and nutrition in the enteral delivery of human milk feedings?

One of the easiest ways to prevent the loss of large amounts of fat is to ensure that all of the feed is delivered to the patient. To ensure no milk is left in the tubing, draw-up the amount of milk required for the feed and deliver all of the milk, including milk within the extension set. If there is no additional milk in the syringe than what was intended for the feed, you will reduce leaving milk that may not be delivered to the patient. Delivering all of the human milk in the tubing increases the chance for all available milk containing fat and nutrition to be administered to the patient.

This also prevents waste of human milk; waste when 1-3 mL of milk is NOT purged (when flushing) or if milk is discarded along with the extension set tubing. This decrease in waste is a direct cost savings and increases the amount of available mother’s own milk. If I do the math, a patient receiving 8 feedings a day x 1-3 mL of milk drawn-up and not delivered to the patient equals an additional 8-24mL a day. This could also be multiplied by number of days, and the amount of undelivered milk increases.

Some NICUs have incorporated the practice of using the extension set for more than one feeding and purging the end of the previous feed at the start of the next feed. This practice does not exceed the HMBANA (2011), guidelines that recommend to “change tubing and syringe every 4 hours.”2 This practice does deliver the entire feed since none of the milk is discarded. Instead it is fed at the beginning of the following next feeding. It is important to remember to purge all of the milk to the patient prior to changing to a new extension set.

Ingawa, et al. recently published a study that examined if freezing-thawing human milk is the main reason for decrease of fat content. Here’s what is interesting: they added a second part to this study to determine if the size and material of the administration tubing used had an impact on fat delivery. The study measured fat content of human milk both pre- and post- enteral infusion, and compared the percent decrease in fat concentration in four different tube sizes and two types material (DEHP-free and PVC-free) as well as the percent decrease in fat concentration. The results found that there is no difference in fat loss related to different size or materials used.3

There is one other point that is significant to mention as it relates to maximizing the delivery of fat. More fat is delivered when the syringe tip is pointed in the vertical position. Fat is less dense than milk, and tilting the tip up will allow the fat to rise to the top and be delivered first. HMBANA (2011), recommends to minimize fat and nutrient loss during gavage feedings by using “milk infusion systems with syringe tip pointed up.”  The key to successfully following this recommendation for syringe tip pointing up is to use an enteral syringe pump that is designed to rotate in the vertical position.

The bottom line is that there are steps you can take to increase the delivery of fat and nutrition with enteral feedings while decreasing the waste of human milk: Administer intermittent and continuous feedings by drawing-up only the amount of milk that you plan to deliver to the patient, and plan to deliver those remaining milliliters of milk in the extension set by purging the extension set milk to the patient. Remember that the size of tubing used for administration set and type of tubing does not increase fat loss. And finally, an enteral infusion pump with the syringe inverted in the vertical position will increase fat delivery.

Look for more on the topic of enteral infusion pumps in a future blog continuing the discussion of delivering full human milk nutrition.