Enteral vs Parenteral Nutrition

Enteral vs Parenteral Nutrition: Definition & Key Differences

Due to certain health issues, some people are unable to eat and digest food normally, so rely on alternative feeding methods, such as enteral or parenteral nutrition. These methods involve food and nutrients being delivered into the body with the use of special pieces of medical equipment, like tubes and catheters.

There are many situations in which a patient may require either enteral parenteral feeding, but it’s important to understand that these two systems are very different, with their own unique features, benefits, and uses. In this parenteral vs enteral nutrition guide, we’ll look at the definitions and uses of enteral and parenteral nutrition, as well as the differences between them.

What Is Enteral Feeding?

Enteral feeding, which may also be known as tube feeding, enteral administration, or enteral nutrition, is a process in which food is inserted into the body with the aid of a feeding tube. The feeding tube delivers food in liquid form directly to the stomach or small intestine, where digestive processes can take place, allowing the nutrients to be absorbed into the blood.

There are many situations in which enteral feeding may be needed. It’s often used for patients who have suffered strokes or have neurological conditions that make it hard or impossible for them to eat and swallow food in the conventional way. Patients with blockages of the throat or stomach may also benefit from this method of feeding.

The key aspect of enteral feeding when compared to other methods, like parenteral feeding, is that it involves the body’s natural digestive processes. This type of feeding is therefore suitable only for patients who still have functioning digestive organs. It’s regarded as an efficient and relatively simple form of feeding with low risks of complications.

What Is Parenteral Feeding?

Parenteral nutrition or parenteral feeding is another type of feeding. It involves the delivery of nutrients in liquid form directly into the bloodstream via a catheter that passes into a large vein, usually around the chest or neck. With this method of feeding, there is no need for any kind of digestion, as the food goes straight into the blood.

Parenteral feeding formulas are made with lots of essential nutrients, including lipids, carbohydrates, vitamins, minerals, and amino acids. This method can also be divided into two main forms: total parenteral feeding, which meets a patient’s entire nutritional needs, or partial parenteral feeding, which is only a supplement to be used in conjunction with other feeding modes.

This type of feeding has a range of uses and advantages. It can be ideal for patients who have some sort of injury, blockage, or disorder that affects their digestive system and makes it difficult or impossible for them to process and digest food naturally. However, parenteral nutrition is quite a complex process and there can be a risk of complications as a result.

Key Differences Between Enteral & Parenteral Feeding

As we can see, even though enteral and parenteral feeding have similar aims – to provide patients with nutrients that they might otherwise be unable to obtain – these feeding methods also have some major differences. Here are some of the main areas in which enteral and parenteral feeding differ:

  1. Delivery Route – The main difference between enteral and parenteral feeding is the delivery route. Enteral feeding tubes are inserted via the mouth and esophagus into the digestive system, whereas the catheters used in parenteral nutrition are inserted directly into the patient’s veins, delivering food into the bloodstream.
  2. Equipment Used – These two feeding methods also make use of very different pieces of equipment. When you use enteral feeding on a patient, a feeding tube is required, for example, but with the parenteral nutrition method, a catheter is used instead to deliver the food into the body.
  3. Overall Method – Parenteral and enteral feeding also differ in terms of the overall method or process that is being used. With enteral feeding tubes, the body’s own digestive system and organs still have a part to play in the process of breaking down food, but with parenteral feeding, the nutrients go straight into the blood to be delivered to the organs.
  4. Complications and Risks – There’s also a difference in terms of the possible risks and complications that a patient might face with enteral and parenteral feeding. In general, enteral feeding is seen as less risky, with fewer potential complications that may arise. It’s a less invasive option and doesn’t involve entering blood vessels in any way, which can be very delicate and risky. 
  5. Difficulty – Following on from the previous point, medical experts also agree that enteral feeding is significantly simpler and less complicated overall than parenteral feeding. The process of inserting a feeding tube into a patient’s body is quite easy when compared to connecting a parenteral catheter to one of their veins.
  6. Use Case – It’s also worth noting that parenteral and enteral feeding methods have different use cases. Enteral feeding is aimed at helping people who still have functional digestive systems but may not be able to feed themselves due to being in a coma or suffering a stroke, while parenteral feeding is for those whose digestive systems are not functioning.

Side Effects of Enteral Versus Parenteral Nutrition

There are a range of potential side effects associated with both enteral and parenteral nutrition.

  • Enteral – Many of the main complications or side effects connected with enteral feeding are related to the digestive system. A patient may, for example, experience, constipation, diarrhea, or dehydration. There’s also a risk of general pain and discomfort in and around the stomach, as well as pain or inflammation in the esophagus.
  • Parenteral – When it comes to parenteral nutrition, the side effects are more likely to occur with the catheter tubing or blood vessels, with common side effects including pain and swelling around the insertion site, phlebitis or inflammation of the vein, and blood clots forming around the catheter.

Potential Risks of Enteral Versus Parenteral Nutrition

There are also various potential risks associated with both of these feeding methods:

  • Enteral – Some of the risks of enteral feeding include food getting into the lungs (aspiration), digestive issues, nausea, vomiting, dehydration, an imbalance of electrolytes, high blood sugar, deficiencies of certain vitamins and minerals, and skin issues.
  • Parenteral – With parental nutrition, there’s a risk of extravasation, which is when fluid flows out of the vein and into the surrounding tissue. In some cases, this can lead to serious tissue damages and even sepsis. There are also risks of dehydration, blood vessel damages, catheter occlusion, and thrombosis, as well as infection.


Why Is Enteral Nutrition Preferred Over Parenteral Feeding?

Enteral nutrition is generally preferred over parenteral feeding for a range of reasons, beginning with the fact that it’s cheaper and simpler. Setting up an enteral feeding tube is a lot easier and less risky than inserting a parenteral catheter. In addition, enteral feeding has fewer complications.

What Are Examples of Enteral Administration?

Some examples of enteral administration include oral administration of solids like pills and tablets, oral administration of liquids like nutrient solutions, softgels, and emulsions, as well as rectal administration of ointments, enemas, and nutrient enemas.

What Are Examples of Parenteral Administration?

Two of the main types of parenteral administration are total parenteral nutrition (TPN) and partial parenteral nutrition (PPN). TPN aims to meet 100% of a patient’s nutritional needs, while PPN only provides a partial amount of their nutritional needs as a supplement or addition to other feeding methods.

Are Suppositories Enteral or Parenteral?

Suppositories are an example of rectal enteral administration, like enemas.

About the Author: CIA Medical

Central Infusion Alliance, Inc. (CIA Medical) is an innovative and customer-oriented medical supply company serving a broad range of medical professionals and organizations. Learn more about CIA Medical.