Nutrients, either a special liquid formula or pureed food, are delivered to a patient through a tube directly into the gastrointestinal tract, usually into the stomach or small intestine.
Tube feeding provides nutrition to patients who are unable or unwilling to eat food. Conditions where tube feeding is considered include protein-energy malnutrition, liver or kidney failure, coma, or in patients who cannot chew or swallow (dysphagia) due to stroke, brain tumor, or head injury. Patients who are receiving radiation therapy or chemotherapy treatments for cancer may also be candidates for tube feedings.
Certain medications may interact with some formulas to inactivate the nutrients or change the way that the drug is absorbed.
A flexible, narrow tube is inserted into some portion of the digestive tract and liquid formulas or liquefied foods are placed into the tube to meet the patient's nutritional needs. The feeding may be pumped into the tube or allowed to drip into the tube continuously or at scheduled feeding times.
A feeding tube can be inserted by a surgical or nonsurgical procedure in several positions along the gastrointestinal tract. The tube may be inserted into the nose
and passed down the throat and through the esophagus. A nasogastric tube is inserted through the nose with the end of the tube reaching into the stomach. A nasoduodenal or nasojejunal tube is inserted through the nose and ends in either the duodenum or jejunum, both of which are portions of the small intestine. This type of tube placement is usually used for short-term feeding. Surgical placement of a feeding tube may be done if there will be a long-term need for feeding that bypasses the upper digestive tract. An esophagostomy creates an opening in the esophagus, a gastrostomy creates an opening into the stomach, and a jejunostomy creates an opening into the jejunum. The feeding tube is then inserted through the surgically created opening.
Tube feedings can be a mixture of regular foods that are blended with liquid to make a consistency that will pass through the tube. Nutritionally balanced liquid products are often more convenient to use and ensure a balance of proteins, fats, and carbohydrates along with vitamins and minerals. Specialized formulas are also available to meet almost any nutritional need. For example, patients with severe burns, protein-energy malnutrition, or slow wound healing may require formulas that are higher in protein. Patients with renal failure may require low-protein formulas with lower concentrations of minerals and vitamins.
The reasons that tube feeding is necessary are discussed with the patient, as is the length of time that the feeding tube is expected to be in place. The specific procedure is also explained to the patient.
Patients with ostomy feeding tubes may have the tube positioned level with the surrounding skin. A cap or button can be placed over the opening so that it can be more comfortably concealed under clothing. The opening and surrounding tissue need to be cleaned and inspected regularly to prevent infection. For patients with a tube inserted through the nose, daily nasal hygiene is important and the mouth and lips should be kept moist. Good mouth care is necessary for any patient with a feeding tube.
Formula from the tube can backup in the esophagus and be breathed into the trachea and lungs, causing aspiration pneumonia. The placement of the tube should be checked frequently and the head of the bed elevated during and after feeding to prevent the solution from moving back up the digestive tract. Feeding tubes can also become clogged and should be flushed regularly with water. If the feeding formula is too concentrated or given too fast, the patient may experience nausea, vomiting, cramping, and bloating. The feeding may need to be diluted with liquid or the rate at which it is given decreased. Diarrhea or constipation can occur if the feeding is not the right composition or does not provide enough liquid. The tube itself can irritate the nasal passage, esophagus, or surrounding tissues.
A patient may be able to return to a normal diet of solid foods after short-term supplementation with formula through a feeding tube. In cases where long-term nutritional therapy is required, all of the patient's nutritional needs will have to be provided by the formula. The balance of fluids, calories, proteins, fats, vitamins, and minerals may need to be adjusted periodically.
If formula feedings are not tolerated by the patient or are inadequate to meet his or her nutritional needs, the patient may need to receive nutrition through an intravenous line (parenteral nutrition). This type of therapy involves delivery of sterile nutrient solutions directly into the bloodstream through a needle inserted into a vein.
"Enteral Nutrition." In The Merck Manual of Diagnosis and Therapy. 16th ed. Ed. Robert Berkow. Rahway, NJ: Merck Research Laboratories, 1992.
Howard, Lyn. "Enteral and Parenteral Nutrition Therapy." In Harrison's Principles of Internal Medicine, ed. Anthony S. Fauci, et al. New York: McGraw-Hill, 1997.
Lagua, R. T., and V. S. Claudio. Nutrition and Diet Therapy Reference Dictionary. 4th ed. New York: Chapman & Hall, 1996.
Altha Roberts Edgren
Duodenum—The upper portion of the small intestine. It is approximately 10 in (25 cm) long and extends from the stomach to the jejunum.
Jejunum—The middle portion of the small intestine. It is approximately 8 ft (2.5 m) long and extends from the jejunum to the ileum.