Enteral nutrition refers to nutrition given through the intestinal system (enteric means by the intestine). This includes by mouth or through a tube into the gastrointestinal tract. Enteral formulas are made up of specialized powders or liquids. These formulas contain nutrients that can contribute partially or totally to an individualís nutritional needs. The physician usually recommends enteral nutrition when an individual is not able to consume enough calories through a normal diet to maintain or gain weight or when the individual has a physical problem with some portion of the gastrointestinal tract preventing normal consumption or digestion of food. Enteral nutrition is frequently ordered for individuals with head and neck cancer, a swallowing disorder, cancer of the esophagus, a birth defect, stroke, HIV/AIDS or other illnesses causing weight loss.
Some enteral formulas may be taken orally and are available in a variety of flavors such as chocolate, vanilla and strawberry. Individuals usually drink these formulas as a supplement to their regular diet but some individuals rely on the formulas for their total nutritional intake.
Other enteral formulas are intended to be given through a tube going into the stomach or a section of the small intestine. These individuals have feeding tubes due to physical problems preventing the normal consumption of food by mouth.
There are several types of feeding tubes. Some begin through the nose and some are placed in the abdomen. The end of the feeding tube may be placed into the stomach or into the small intestine. The most typical feeding tube is a gastrostomy tube. The tip of this tube rests in the stomach and the top 6-7 inches exits out of the body in the abdominal region. A naso tube starts at the nose and is fed down the back of the throat until the tips rests in the stomach (nasogastric) or in the small intestine (nasoduodenal or nasojejunal). Naso tubes tend to be more temporary than abdominal feeding tubes. A jejunostomy tube looks much like a gastrostomy tube from the outside, but the tip lies in a section of the small intestine instead of the stomach.
Tube feedings are given one of three ways:
The first is by bolus or syringe feeding. A large syringe, usually 30-60 ml (milliliters), is connected to the individualís feeding tube. The enteral formula is poured into the syringe and allowed to flow into the stomach or small intestine by gravity. The rate is controlled by the height at which the syringe is held. Feedings should take at least 15 minutes and are typically administered intermittently throughout the day. This is the simplest method of tube feeding.
The second method is to attach a bag and tubing (feeding set) to the feeding tube instead of a syringe. A larger quantity of formula may be poured into the bag than is allowed with the syringe method. A roller clamp located on the feeding set controls the rate. The prescribed amount of formula can infuse over a wide range of times depending upon what the individual can tolerate and what the physician has ordered.
The third method utilizes an enteral pump to infuse the formula at a controlled rate. The feedings can be given continuously or may be administered over several hours throughout the day depending on an individualís needs. Pumps are typically ordered for all feedings going into the small intestine and for those individuals who cannot tolerate gravity or bolus feedings. Most children receive their tube feedings through an enteral pump.
The age and mobility of the individual and the specific tube feeding order determines what type of enteral pump is used.
Many individuals receive all of their tube feeding during the night. An enteral pump mounted on an IV pole can work well for most of these individuals. These pumps are very easy to operate and will continue to operate by battery if the individual unplugs the power cord to move between rooms.
Some individuals receive tube feedings during the day and require increased mobility. These individuals utilize ambulatory pumps that can be carried in a backpack. Many individuals receiving tube feedings are able to go to school or to work. Infants and toddlers that must be carried and very active children also utilize ambulatory pumps. A small disadvantage of the ambulatory pumps is that some are more difficult to operate than the pole-mounted variety.