In our daily life we are eating continuously , several times a day, in most things without thinking about the complex process we carry out both at the level and behavioral.

But sometimes it is not possible to feed ourselves voluntarily: imagine that we are in a coma or that we suffer from some kind of illness that prevents us from eating. If nothing is done, the organism would end up dying of starvation.

Fortunately, we have mechanisms that allow us to continue to provide nutrients artificially: enteral nutrition .

Enteral nutrition: what is it?

Enteral nutrition is, along with parenteral nutrition, one of the two types of artificial nutrition available in medicine. It is a support technique in which the different nutrients that the patient may need are introduced into the body, generally using a tube that goes directly into the intestine or stomach.

This technique avoids the need for food to pass through the mouth and trachea, not requiring voluntary movements to acquire the nutrients . However, applying enteral nutrition requires the digestive system to be able to exercise its normal functions when it comes to absorbing the nutrients supplied.

Enteral nutrition helps to prevent, among other things, protein self-catabolism (in other words, the body consuming itself in order to obtain nutrients), the weakening of the immune system (with the consequent risk of infection), bacterial translocation (bacteria in the digestive tract itself causing an infection) and atrophy of the digestive system. Administration can be continuous or discontinuous depending on the patient’s needs.

Types of Enteral Nutrition

There are different methods by which enteral nutrition can be performed. One of the ways to classify the different types of enteral nutrition is according to where the tube is placed and how far it goes.

1. Nasogastric tube enteral nutrition

In this procedure, a tube is placed through the nose and will travel to the stomach , where the nutrients will be delivered. This is usually the most common mechanism, unless there is a risk of pulmonary aspiration of the contents of the intestine.

If the patient is conscious it will be introduced through the nostrils and the patient will be asked to swallow saliva in order to direct the tube towards the digestive tract and not towards the respiratory system. Despite this, the subject’s collaboration or awareness is not necessary to place it.

2. Enteral nutrition by nasoenteral tube

The procedure is the same as above, except that in this case the catheter will be taken to the intestine.

3. Enterostomy

When feeding through a nasoenteric or nasogastric tube is not feasible there is another procedure: the enterostomy. In this case, a tube is not introduced through the usual routes, but is placed directly through the skin. More than a tube we would be looking at a type of catheter. It is also used when the patient is not expected to be able to feed himself in more than four weeks. There are three main techniques for enterostomies.

Pharyngostomy

A probe is placed directly into the pharynx.

Gastrostomy

This procedure is based on the placement of a tube that reaches the stomach, but in this case through the skin .

Jejunostomy

Like the gastrostomy, a tube is inserted through the skin into the target organ, in this case the area of the intestine called the jejunum .

What kind of substances are introduced into the body?

Enteral feeding involves introducing certain nutritional substances into the body, varying these substances according to the needs of the patient . They will vary if, for example, the patient has kidney or liver failure, diabetes, or respiratory problems. Also the developmental state of the subject (e.g. in babies mother’s milk is used). Among other things, the caloric and protein content is taken into account (it can be hyper, normo or hypocaloric/protein).

As for the form in which the nutrients are presented, in general we can find polymeric (in which intact proteins are provided), peptide (hydrolyzed proteins) or elemental (directly in the form of amino acids) formulas. There are also special diets for those patients with specific problems.

The most common formula is which implies a polymeric, normocaloric and normoprotein diet , but as we have already said the choice of components will depend on the patient and his or her needs.

In what cases does it apply?

Enteral nutrition is the technique of choice in all situations where the patient is malnourished or at risk of malnourishment due to the existence of an inability to swallow or the refusal to swallow voluntarily, due to injury, illness or mental disorder . In other words, it is used both in patients without the capacity to swallow, with a very diminished capacity or who refuse to do so despite having the functional capacity to do so.

However, to be able to apply it, the digestive system needs to have a minimum of functionality when it comes to digesting and/or absorbing nutrients. It can be used in subjects of any age, from babies to the elderly.

It is essential in situations where the subject does not have the capacity to swallow , such as a coma, or when there are alterations in the pharynx that make swallowing impossible.

It is also useful in some diseases in which although it has functional capacity to do so, the patient cannot ingest because of problems such as bronchodysplasia or some cardiopathy. Or when ingestion is impossible because it causes reactions such as vomiting . Another case occurs in situations where the body needs more nutrients than the subject, despite eating, is able to provide.

On the other hand, also is recommended in premature babies , in order to prevent different diseases. Finally, it is used in mental disorders such as anorexia, forcing nutrition in cases of severe underweight that can lead to death,

Contraindications and risks

Enteral nutrition is a very beneficial technique that provides the body with the necessary food when it cannot eat by itself. However, in some cases this type of feeding may be contraindicated due to the existence of problems in the digestive tract itself.

The main contraindication is the presence of obstructions, bleeding or perforations in the stomach or intestine .

The use of enteral nutrition may also pose some risks. There may be blockages or displacement of the tube or possible metabolic complications if adequate nutrition has not been given. Vomiting and nausea may occur, as well as diarrhea and reflux. Although rare, pulmonary aspiration of GI tract contents may occur.

Bibliographic references:

  • Álvarez, J.; Peláez, N. and Muñoz, A. (2006). Clinical use of Enteral Nutrition. Nutrición Hospitalaria, 21 (Supl.2); 87-99. Alcalá de Henares, Madrid.
  • Lama, R.A. (n.d.). Enteral nutrition. Diagnostic and therapeutic protocols of Gastroenterology, Hepatology and Pediatric Nutrition. SEGHNP-AEP. La Paz University Children’s Hospital. Autonomous University of Madrid.
  • Ostabal, M.I. (2002). Enteral nutrition. Medicina integral, 40 (7). 310-317. Elsevier.