What Is Parenteral Nutrition?

Medically Reviewed by Dan Brennan, MD on June 02, 2021
Written by WebMD Editorial Contributors
4 min read

Parenteral nutrition (PN) is the medical term for receiving nutrients intravenously (by IV, meaning by a needle in your vein). There are two types of parenteral nutrition: total parenteral nutrition (TPN) and partial parenteral nutrition (PPN).

If you receive total parenteral nutrition, you receive all your essential nutrition via an IV. If you receive partial parenteral nutrition, you may still eat some foods using your digestive system.

Nutrition is very important. The food we take in gives our body the ability to function. It's especially important for children. A lack of proper nutrition can lead to developmental delays and slow growth. Parenteral nutrition helps some people get all the nutrients they need to be healthy. 

A person of any age, including infants, can get parenteral nutrition. You can receive parenteral nutrition for as long as is needed. 

If you have a condition that prevents you from absorbing nutrients properly, you may need parenteral nutrition. Specific conditions that may require PN include:

If you have a well-functioning digestive system, or you don't have good vein access, then parenteral nutrition isn't a good option for you.

First, a medical team, often including doctors, nurses, and nutritionists, will determine if you need parenteral nutrition. They'll work together to figure out exactly how many calories, nutrients, and fluids you need as part of your nutrition plan. 

There are short-term and long-term central venous access devices (CVAD). Your medical team will work together to choose the right one for you.

The options include:

  • Non-tunneled catheters. These are best for short-term PN.
  • Tunneled catheters. These are better for long-term PN because they are less likely to cause infections.
  • Peripherally inserted central catheters (PICC). This is another option for long-term PN. This is a catheter that goes into the superior vena cava, a large vein that supplies blood directly to the heart.
  • Implanted devices. These surgical implants allow you to get PN via a special needle.

When you receive PN, your nutrition does not go through your digestive system. It goes straight into your bloodstream. 

The main risks of PN are:

  • Infection
  • Clogging of the catheter
  • Breakage of catheter
  • Blood clot around the catheter
  • Nutritional imbalances 
  • Overfeeding
  • Atrophy of the gastrointestinal tract
  • Fatty liver
  • Reduced flow of bile from the liver (cholestasis)

Experts recommend following sanitary protocols to prevent infections. This includes frequent hand washing, wearing gloves when handling the port or catheter, and monitoring the port for signs of infection. 

To prevent clogs, you can flush the catheter with water to clear it out. A nurse can also use an anti-clotting agent to prevent clogs.

Replace any broken or cracked catheters as soon as possible.

Many people can continue to work, go to school, or do some of their usual activities on parenteral nutrition. However, your lifestyle while using parenteral nutrition will likely be determined by the underlying condition that causes you to use PN. You should work with your medical team to address your desires in terms of working and personal hobbies or activities.

Experts usually recommend avoiding contact sports and swimming while receiving PN. However, lower-impact activities with less risk of damaging or ripping your IV port, like biking or running, may be a good option for people on PN. Depending on your condition, staying active can be helpful.

Enteral nutrition is any time you use your digestive tract to take in nutrients. This includes the normal way of eating foods through your mouth. It also includes tube feeding. This is when you have a tube inserted into your stomach.

This tube may be inserted through your nose or surgically implanted into your stomach. The procedure to implant the tube into the stomach is called a gastrostomy.

When the tube is inserted through the nose, it is called a nasogastric tube. A nasogastric tube is often used for short-term nutritional help. A surgically inserted tube is often used for more long-term nutritional assistance.

The risks of enteral nutrition via a tube include food entering the lungs, nausea, diarrhea, nutritional imbalances, and irritation or infection at the site of the tube's entry.

These solutions are for people who have well-functioning digestive systems but who may have difficulty chewing or swallowing, or who simply need help taking in more nutrients.

You can get both parenteral and enteral nutrition at home. Both require following your doctor's recommendations and some training on how to use your IV port or feeding tube.