Total parenteral nutrition (TPN) is a feeding method that allows people to receive nutrients intravenously. “Parenteral” refers to the outside of the digestive tract. Enteral nutrition is food or nutrients that are received through the digestive tract, which in humans runs from the mouth to the anus.
Total parenteral nutrition refers to instances where people receive all of their nutrition through a vein. Parenteral nutrition can be partial, when it’s supplementing the diet of a malnourished child, for example. When total parenteral nutrition is used, it’s because a person can’t receive nutrition through their digestive tract at all.
In these cases, it’s not just that someone can’t eat. Their ability to absorb nutrients, digest foods, and use their digestive system as a whole is not there.
In newborns, total parenteral nutrition is used most often when babies are born prematurely, are living with conditions that make them very sick, and need surgery to recover. Other reasons someone might need TPN include a lack of blood flow to the digestive system, obstructions in the intestines, bleeding in the digestive tract, inflammatory bowel disease, and short bowel syndrome.
Total parenteral nutrition is delivered through a central vein to the body, usually the superior vena cava. The superior vena cava runs straight to the heart to deliver more nutrients simultaneously.
Parenteral nutrition contains some amount of the six things you need to live. These are carbohydrates, fats, proteins, water, vitamins, and minerals. The formula can be customised to your nutrition needs. Parenteral nutrition can sustain someone for a long time, even a lifetime.
How are people prepared for total parenteral nutrition?
A healthcare team determines your or your newborn’s needs based on medical history and history of the pregnancy and birth, as well as looking at your current weight and any relevant lab results. A care team, including your doctors, nurses, and anyone else caring for you or your newborn, plans what goes into parenteral nutrition, and a nutrition specialist prepares it for you.
There are three ways to deliver total parenteral nutrition, including a peripherally inserted catheter, which babies typically have put in.
Peripherally inserted catheters are placed in the vein and guided into the superior vena cava while the needle port stays outside the body. These are used when TPN is required for a short time.
A fully implanted catheter is entirely under the skin. A port is attached at the other end of the needle and under the skin.’
External catheters go into and out of the skin at separate points.
The main benefit most patients receive from TPN is the ability to let their digestive system heal. It can be lifesaving for newborns when their digestive tract hasn’t fully developed yet.
There is a higher risk of complications than when using enteral nutrition or eating orally, including infections, blood clots, loss of muscle tone in the digestive tract, high or low blood sugar, liver disease, and lack of good mineral density in the bones.
If you or your infant is on total parenteral nutrition, your healthcare providers will try to transition you from TPN to eating orally or enteral nutrition – like a feeding tube – as soon as possible. The outlook for a long, healthy life is good with a transition to or back to a healthy diet. TPN can seem extreme, but sometimes it’s necessary to sustain life or save it for some time.