Parenteral nutrition is a method of feeding in which nutrition goes directly to the bloodstream. A person may need it if feeding through the gastrointestinal (GI) tract cannot fulfill their body’s nutrition needs.

If someone needs supplemental nutrition, a doctor may recommend feeding through tubes or oral supplements. However, if these cannot provide adequate nutrition, the doctor may suggest parenteral nutrition. This method delivers nutrients through a catheter (a type of flexible tube) inserted into a vein.

A person can receive parenteral nutrition for days, weeks, months, or years. They can receive it in the hospital and at home.

This article will explain what parenteral nutrition is, how it is different from enteral nutrition, the various types, reasons to have it, potential complications, and what someone can expect.

An IV bag used in parenteral nutrition -1.Share on Pinterest
digicomphoto/Getty Images

Parenteral nutrition is a feeding method in which nutrition goes into a vein through a catheter. Calories and nutrients go directly into the bloodstream rather than going through the GI tract first.

Depending on someone’s needs, parenteral nutrition can deliver one or all of the following:

While parenteral nutrition goes directly into a vein, enteral nutrition uses the GI tract for feeding.

Enteral nutrition uses tube feeding or oral methods, such as regular eating and drinking, to provide nutrition. Tube feeding is when a tube placed through the nose, mouth, or skin delivers nutrients and calories directly to the GI tract.

Doctors recommend parenteral nutrition when enteral methods, such as regular eating, drinking, or tube feeding, cannot give someone sufficient nutrition. Some conditions that can cause someone to need parenteral nutrition include:

  • bowel blockage
  • disease or treatment resulting in intestinal failure
  • inaccessible GI tract
  • high output fistulas
  • a need to rest the bowels
  • recurrent vomiting
  • oral or tube feeding not working

Parenteral nutrition can be short- or long-term and can deliver partial or total nutrition needs. Healthcare professionals typically categorize types of parenteral nutrition as either:

  • Partial parenteral nutrition: This is often given as a supplement to a person’s diet if they are eating but lacking nutrients.
  • Total parenteral nutrition: This is complete nutrition via an intravenous (IV) tube for people with impaired digestive function.

A healthcare professional may also categorize it based on where the tube goes:

  • Central parenteral nutrition: This is when a person receives nutrition through a large central vein, which allows for higher concentrations of nutrition and calories. This is a common way for a person to receive total parenteral nutrition.
  • Peripheral parenteral nutrition: This is when a person receives nutrition through a smaller vein in the neck or one of the limbs. A healthcare professional may recommend this method for partial parenteral nutrition temporarily because it is quicker and easier to access a peripheral vein than a central one.

Experiences vary with the type of parenteral nutrition.

A person can receive nutrition delivery continuously or in cycles. For example, someone may receive nutrition for only a few hours each day.

A healthcare professional will typically insert parenteral nutrition from a person’s bedside in a hospital, in an operating room, or in a radiology department. A nurse with special training can insert a peripherally-inserted central catheter (PICC) to deliver nutrition in a person’s home.

If someone needs to continue parenteral nutrition at home after starting in a hospital, they will undergo routine monitoring and work with a team of healthcare professionals to support their care.

Longer-term methods that involve home care may require cleaning and care by the person or others. In addition to dressing and cleaning the site, a catheter such as a PICC may require flushing.

Risks and complications can vary with the type of parenteral nutrition. For example, it may take multiple tries to determine the correct concentration of nutrients a person needs.

Other complications and risks may include:

  • a broken, cracked, or clogged catheter
  • nutrient imbalances or concentrations that are too high or too low
  • infection
  • mild to severe liver dysfunction
  • bleeding
  • damage to surrounding structures

Parenteral nutrition delivers nutrition directly into the bloodstream through a vein, bypassing the GI tract.

It may deliver partial or full nutrition, and there are various short- and long-term options. Some methods work via the arm or neck and others into or below the chest. Nutrition delivery may occur constantly or in intervals.

Risks can include issues with nutrient amounts, problems with catheters, infection, liver dysfunction, bleeding, and tissue damage.

When discussing parenteral nutrition with a doctor, a person should consider asking about which type best suits their health and lifestyle needs, what different methods involve, and ways to limit complications.