What is Parenteral Nutrition (PN)?

Sometimes a person can't get all the nutrients they need from food, or from liquid feeds that bypass the mouth and are given 'enterally' (ie straight into the intestines) because of problems with the gut (also known as the gastrointestinal tract).

'Parenteral' simply refers to the giving of medicines or treatments into the body via a route other than the mouth or intestines. Parenteral nutrition means giving nutrition into the body by a vein so directly into the bloodstream (or intravenously). Some people need to have all their nutrition via the parenteral route, whereas others may need PN to top up what they get through eating and drinking.

Who needs PN?

PN is only given to someone (including babies, children or adults) when it's clear they won't be able to get all their nutrition using the gastrointestinal tract alone. In this case, a person has what's called 'intestinal failure'. Sometimes, intestinal failure can happen for a very short time only, for example if someone has had an operation on their intestines, and PN may not be needed. In other cases, if the condition that has caused the intestinal failure is something that lasts longer than a few days, then PN may be necessary.

Reasons for needing PN

A short gut (short bowel syndrome)
A leaking (perforated) or a blocked (obstructed) gut
A gut that's not digesting food or liquids properly
Conditions that have happened before someone is born, or in childhood

How PN is given

For the majority of people who will be having their PN at home, a device called a central venous catheter is used to get the PN into the body. Catheter is the medical name given to what is essentially a special tube that goes directly into a person’s vein. Humans have lots of veins that differ in size and location, and ‘central’ simply refers to a large vein that is close to the heart. There are different types of central venous catheters, and the one that is used is decided by the NHS clinical team.

For home parenteral support, a person will usually have the central venous catheter going into the upper part of the chest. To get the PN (and/or other intravenous fluids) into the body, it first has to be connected by a longer tube to the catheter, then a pump is used to move the liquid from the bag to the vein.

It's extremely important that anyone with a central venous catheter makes sure it’s looked after carefully and properly. Catheter care is something that will be discussed with the NHS clinical team, and anyone going home on parenteral nutrition or intravenous fluids (or family or carers) will need to be trained in looking after their catheter. While this might seem daunting at first, there’s lots of support on hand, including from the specialist nursing team at Calea.