October 19, 2021
October 19, 2021

Enteral vs. Parenteral Feeding & Nutrition

Sometimes we are presented with situations that prevent us or a loved one from receiving adequate nutrition, such as an illness, malnutrition, surgery, or GI disorders. Under these critical care conditions, nutrition must be supplied through a feeding tube in order to provide adequate nutritional status.

In clinical nutrition, there are two tube feeding methods called: enteral and parenteral feeding. 

Dietitians and clinicians offer nutrition support to provide and manage enteral nutrition and parenteral nutrition in diverse patient populations from pediatrics to geriatrics.

Keep reading to learn more about enteral and parenteral nutrition, the difference between them, and the advantages and risks of each.

What is Enteral Feeding?

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Enteral feeding, also called tube feeding, refers to food intake in liquid form via the gastrointestinal tract with either a tube through the mouth or a tube that goes directly to the stomach or small intestine. Temporary or short-term feeding tubes may also be used for tube feeding through the nose or mouth and into the stomach or small intestine.

People that require enteral feeding usually have a condition or injury that prevents eating a regular diet by mouth, but their GI tract can still function. Thus, allowing them to receive nutrition and keep their GI tract working.

Enteral feeding may make up the entire caloric intake of a person or may be used as a supplement.

Enteral feeding formulas are specifically designed to fulfill nutritional requirements according to individual needs from adults to children and infants. Some formulas have a higher protein or fiber content and are also custom-made for specific ill patients, such as those with liver conditions (renal failure) or pancreatitis.

What is Parenteral Feeding?

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Parenteral feeding involves receiving nutrition intravenously in the form of a liquid mixture of nutrients to meet specific nutritional needs bypassing the normal digestion in the gastrointestinal (GI) tract and given directly into the bloodstream. This can occur due to injury, illness, or intestinal malabsorption problems.

In clinical nutrition, when Parenteral nutrition (PN) is needed to provide all of your daily nutrition, it is called total parenteral nutrition, or TPN. TPN is a mix of protein, sugar, lipids (fats), vitamins, electrolytes, and minerals given through tubing placed into a large vein in the central part of the body called a central line. 

When a central line is not available or when parenteral nutrition is only supplemental, PN may be given through a vein in the arm or the back of the hand through a small tube (IV catheter). In these cases, the solution given is called partial parenteral nutrition or PPN.

Enteral vs. Parenteral Nutrition

Both types of nutrition therapy aim to provide individuals with the proper nutrients, lipids, carbohydrates and proteins to prevent risk of malnourishment and subsequent adverse effects in ill adults or children.

The difference between these two types of clinical care is that enteral nutrition is administered through a feeding tube via the stomach or small intestine and parenteral nutrition is administered through a traditional intravenous (IV) line or via a central IV surgically placed in the central part of the body.

Who needs Enteral Nutrition?

Enteral nutrition may become necessary when a person is at risk of malnourishment due to common conditions such as:

  • A stroke
  • Cancer
  • Failure to thrive or inability to eat in young children or infants
  • Anorexia
  • Dysphagia (difficulty swallowing)
  • Neurologic or movement disorders (Parkinson's disease or Alzheimer's disease)
  • Critical injuries

If a person can't eat enough, they're at risk for malnourishment, weight loss, and serious health issues. 

The main types of enteral tubes include:

  • Nasogastric tube (NGT) starts in the nose and ends in the stomach.
  • Orogastric tube (OGT) starts in the mouth and ends in the stomach.
  • Nasoenteric tube starts in the nose and ends in the intestines.
  • Oroenteric tube starts in the mouth and ends in the intestines.
  • Gastrostomy tube is placed through the skin of the abdomen straight to the stomach.
  • Jejunostomy tube is placed through the skin of the abdomen straight into the intestines (jejunum).

Who needs Parenteral Nutrition?

In some cases, enteral feeding may not be an option. If there's risk for malnutrition and the GI system is not functional, parenteral feeding is needed.

With the same goal, parenteral nutrition aims to prevent malnourishment specifically in individuals with gastrointestinal issues that prevent them from properly digesting and absorbing food. 

People can live well on parenteral nutrition for as long as it is needed. Many times, parenteral nutrition is used for a short time; then it is lessened or discontinued when the person begins to eat normally again, while others may require PN at home for a lifetime.

Common conditions that may benefit from parenteral nutrition include:

  • Crohn’s disease
  • Cancer
  • Short bowel syndrome
  • Ischemic bowel disease
  • Low blood flow to the bowels
  • Critically ill patients
  • Severe acute pancreatitis.

Advantages of enteral nutrition and parenteral nutrition

One form of tube feeding isn’t necessarily better than the other, it all depends on personal needs.

Although the data is still unclear, there is a tendency in clinical trials to support choosing EN over PN when patients require nutrition support as a less invasive procedure.

The advantages of choosing enteral feeding include:

- cost-effective and simple procedure

- fewer complications

- stimulates intestinal blood flow and maintains GI mucosal barrier

- provides the necessary nutrients

-  associated with less sepsis and metabolic complications

The advantages of choosing parenteral feeding include:

- can be started early

- does not rely of gastric/intestinal function

- less treatment interruption

- provides the necessary nutrients

What are the risks of enteral or parenteral nutrition?

Enteral and parenteral nutrition are both considered safe and are life-saving but complex therapy, which is not without risk of complications, such as:

- food entering the lungs (aspiration)

- constipation or diarrhea

- improper absorption of nutrients

- nausea or vomiting

- dehydration and electrolyte abnormalities

- high blood glucose levels

- vitamin and mineral deficiencies

- decreased liver proteins

- Feeding tubes inserted through the nose can cause irritation of the nose or throat

- acute sinus infections, and ulceration of the larynx or esophagus. 

- Feeding tubes inserted through the skin of the abdominal wall, such as gastrostomy or jejunostomy tubes, can become clogged or displaced, and wound infections can occur.

Final Thoughts

Both enteral and parenteral nutrition protocols require a big adjustment and may feel overwhelming at first. However, once treatment begins the results lead to enhanced energy and improved health making the effort worth while. 

Along the way, your healthcare provider will perform the appropriate tests and make the necessary adjustments to ensure proper nutrition and comfort. The amount, type, and route of nutrition is tailored specifically to each patient with the goal of improving patient outcomes, minimizing infections, and allowing patients to live their lives as normally as possible.

You can refer to our extensive line of enteral feeding formulas and always reach out to us if you have any questions.

Written by Karina Lima

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