Question 1

What is Parenteral Nutrition (PN)?

Accepted Answer

Parenteral nutrition (PN) is a liquid that provides nutrition directly into the body's large veins. It provides you (or your child) with all of the nutrients, fluids, vitamins, and minerals needed to fuel the body.
 
Since PN is infused straight into the bloodstream, it bypasses the intestine. This is beneficial in short bowel patients and other gastrointestinal disorders where the intestine does not absorb efficiently.
 
Other common terms for parenteral nutrition include: hyperalimentation (very old term), total parenteral nutrition (TPN), home parenteral nutrition (HPN), Peripheral Parenteral Nutrition (PPN), or Total Nutrient Admixture (TNA).

Question 2

What is the difference between parenteral nutrition (PN) and enteral nutrition (tube feeds)?

Accepted Answer

Enteral nutrition, also known as tube feeding, is used when a person's digestive system works to some extent. The feeding tube is given directly into part of the digestive system. 
 
Parenteral nutrition (PN) bypasses the digestive system entirely and goes directly into the bloodstream, where the nutrients are absorbed.
 
Individuals may be just on PN or enteral nutrition, or in some cases, an individual may be on both parenteral nutrition (PN) and enteral nutrition. 
 
To learn more about enteral nutrition visit this page.

Question 3

Why does someone require PN?

Accepted Answer

Parenteral nutrition is given to people with certain gastrointestinal disorders, such as short bowel syndrome, who are unable to absorb enough nutrients.
 
PN is delivered directly into the bloodstream (bypassing the gastrointestinal tract) through a central venous catheter (CVC).
 
Common reasons people require PN (this list is not all-inclusive, rather, a snapshot):
Crohn's and Ulcerative Colitis
Motility disorders, such as chronic intestinal pseudo-obstruction (CIPO)
Malabsorption Syndromes
GI Fistulas
Cancer, particularly that of the GI tract
Short bowel syndrome from congenital conditions 
Stroke
Cystic fibrosis
ALS
Parkinson's Disease
Ischemic bowel disease
Necrotizing Enterocolitis (NEC)
Pancreatitis
Post-bariatric surgery with complications

Question 4

How is parenteral nutrition (PN) administered?

Accepted Answer

A catheter (small tube) is placed in one of your main blood vessels. Common areas include the neck and chest. If there are access issues, the catheter may be placed in the leg or groin The catheter is known as a central venous catheter (CVC) or central line, and delivers the PN solution directly into your bloodstream.

PN is generally administered in these mixtures:
2 in 1 refers to the administration of amino acids and dextrose in 1 IV bag with the lipids administered separately.
3 in 1 combines amino acids, dextrose and lipids in 1 IV bag.
 
Go to section two to read more about central venous catheters (CVCs). 
 
If you would like an overview of CVCs you can download this handout if you are a caregiver of a child or this handout for adults: Patient's Guide to CVCs

Question 5

What are the components of PN?

Accepted Answer

PN supplies the primary nutrients your body needs to sustain life, including the three primary sources of energy for your body:
 
1. Carbohydrates: This gives your body calories and is the primary energy component in PN. It is usually in the PN as glucose.
 
2. Protein: Helps your body repair tissue, build muscle, fight infections, and carry nutrients through the body.
 
3. Fat: Another good source of calories and energy. It also is needed to absorb vitamins A, D, E, K, helps to protect your vital organs, and conserve heat.
 
In addition to the three main components, PN also contains micronutrients your body needs to function:
 
1. Vitamins: Usually, you are required to add these to your PN solution when you are on home PN. These are what turn the PN solution yellow. Examples: vitamins A, D, E, and K.
 
2. Minerals: These may also be added to PN. Examples are zinc and copper.
 
3. Electrolytes: These are important for the function of most systems of the body. Examples: calcium, potassium, phosphorous, magnesium, and sodium.
 
4. Water: Water is important to keep you hydrated and your kidneys functioning.
 
Medications: Sometimes you may add mediations to your PN solution. Commonly added medications include:
Insulin: This helps to control your blood sugar.
Anti-acid: This helps with stomach acid secretion.
Octreotide: This is an anti-secretory medication and can help decrease diarrhea.

Question 6

What are the types of lipid formulations for PN?

Accepted Answer

1. Intralipid: This is a soybean oil lipid emulsion (SOLE). SOLEs contain high amounts of a plant-based cholesterol-like compound called phytosterols, found in vegetable oils. These have been found to contribute to the development of cholestasis and disruption of bile acid homeostasis. 
 
2. Mixed-lipid emulsions: These lipid emulsions contain various amounts of plant-based oils, fish oils, and medium-chain triglycerides (MCTs). The most commonly known is SMOFlipid® which consists of: 30% soybean oil, 30% MCTs, 25% olive oil, 15% fish oil. SMOFlipid® is currently indicated for use in adults "as a source of calories and essential fatty acids for PN when oral or enteral nutrition is not possible, insufficient, or contraindicated."
 
3. Omegaven®: This is a fish-oil lipid emulsion (FOLE). It contains minimal phytosterols and is rich in omega-3 fatty acids. It is currently FDA approved for children with parenteral-nutrition associated cholestasis. 
 
Research is continuously ongoing on the best lipid formulation to help prevent parenteral-nutrition associated liver disease (PNALD). To stay up-to-date on nutrition news, visit the Oley website.

Question 7

How is PN started and cycled?

Accepted Answer

Every individual is different, but generally, PN is started as an inpatient in the hospital. The reason for this is that your team needs to closely monitor you (or your child) very closely at the beginning to ensure that your electrolytes and other blood levels stay in balance.
 
Since many people starting PN are malnourished, they also are at risk of something called refeeding syndrome (see PN complications). 
 
At first, most individuals will start PN on a 24-hour continuous cycle. This means the PN runs throughout the entire day.
Initially, your PN will not contain all of the calories and nutrients your body needs.
Gradually over a few days to weeks your team will increase the glucose (energy/calories) in the PN until the full nutritional requirements are met.
Once met, your team will likely start to 'cycle' your PN.
Note: Not all people will be able to cycle PN and may have to remain on a continuous infusion. Your team will determine the best option for you.
Cycling your PN means that they will decrease the amount of time that your PN runs over.
Typically it will go down in increments, such as from 24 hours to 18 hours to 16 hours and finally ending at a 12-hour cycle.
Most people like to do their 12-hour cycle overnight; therefore, they can be free from PN throughout the day.

Question 8

What is important to monitor while on PN?

Accepted Answer

This will vary per center, however, it is usually important to record:
Weight
Fluid intake and output
Temperature
Urine-dipstick-for-sugar results or blood sugar monitor
During the first few weeks or months, you usually will need weekly bloodwork. If you have been on PN for a long time, the frequency of blood monitoring may decrease.