What is Total Parenteral Nutrition (TPN)?

Total parenteral nutrition (TPN) is a type of nutrition provided to clients intravenously, instead of through the digestive system. Parenteral nutrition can be given as a complete means of nutrition or as a partial supplement. Many clients will need TPN due to illness, injury or surgery.

So let’s dive into nursing indications, considerations, and goals of administering TPN.

What is TPN?

TPN is the administration of a nutritionally adequate hypertonic solution consisting of dextrose, amino acids, protein, minerals, fats, vitamins, and trace elements through an intravenous catheter.

TPN is composed mainly of highly concentrated and thick solutions that are given long-term. It’s customized for each client’s needs, including the exact amount of calories and nutrients necessary for total nutritional needs.

Clients are administered TPN usually through a peripherally-inserted central catheter (PICC) line, or a central venous access device CVAD (catheter). This is because there is less risk of thrombophlebitis and vein damage.

When to Provide TPN Nutrition

The primary purpose of providing TPN is to maintain a positive nitrogen balance. Positive nitrogen balance means the body is in an anabolic or growing state and not experiencing a catabolic breakdown.

TPN replenishes the nutrients lost due to malnourishment, vomiting, diarrhea, or illness. The end goal for administering TPN is to keep the client at a proper weight through adequate feeding (and to provide optimal health if at all possible).

TPN also aims at:

• Keeping the patient’s nutrition in a healthy state.
• Preserving muscle mass, thus, lessening body fat.
• Managing proper metabolism.
• Sustaining continuous circulation inside the body.

Advantages of TPN

One of the main advantages of TPN is that it decreases the risk of developing gut-related sepsis because the stomach is no longer used as the primary route for nutrition.

This is especially beneficial for patients with small bowel obstruction or are prescribed NPO (nothing by mouth). It’s also cost-effective for medical institutions.

PPN vs TPN

Peripheral parenteral nutrition (PPN) and Total parenteral nutrition (TPN) involve administering nutrients through a catheter in the peripheral or central veins.

PPN and TPN are used to prevent the harmful effects of malnutrition in a person unable to eat because of illness. However, there are some key differences between the two.

With PPN, nutrients are delivered directly into major blood vessels outside the heart. PPN can’t be used for very long without risking serious complications such as infection and blood clots, so it’s generally only prescribed for patients who need it for less than six weeks at a time.

On the other hand, TPN involves delivering nutrients directly into a person’s veins through an IV line, which can be done in an outpatient setting or inpatient facility, depending on their condition and needs.

While this method has many advantages over PPN (such as using it for much longer periods of time), it also comes with some risks. This could include sepsis caused by bacteria entering through the infusion site on the skin or bloodstream.

Nursing Considerations for Total Parenteral Nutrition

When taking care of a patient who has a TPN line, health care providers (HCP) and the nurse at the bedside should give high regard to the following:

The Nature of the Contents

TPN is broken down food turned into a liquid form. It’s very thick and viscous, so it’s necessary to deliver it through either a PICC line or a central venous access device (CVAD) to decrease the risk of thrombosis in the veins.

Peripheral Infusion

Low-concentration TPN can be given peripherally via an 18 gauge angiocath but is not ideal for infusions longer than two weeks.

Indications for TPN

Clients are usually prescribed TPN when they must be NPO for an extended time period. As a result of this prolonged status, the body is no longer receiving the right amount of nutrients required for proper functioning. These clients will be given D5 ½ normal saline to keep blood glucose within normal limits and prevent catabolism (the breaking down of large molecules)

Read our complete IV solutions NCLEX review here.

What are the disorders or diseases that usually require TPN?

1. Clients with pancreatic abnormalities like pancreatitis. Eating can cause stress to the pancreas. Therefore, TPN is necessary.
2. Ulcerative colitis patients are also given TPN.
3. Clients suffering from small bowel obstructions and unable to consume anything are also candidates for TPN.

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