You can have liquid food by means of 2 types of tube feeding:
- parenteral nutrition is when you have food directly into a vein
- enteral nutrition is when you have food directly into the stomach or bowel
Giving food directly into a vein
If you have a feed into your bloodstream through a drip into a vein, it is called parenteral nutrition (PN).
With parenteral nutrition (PN) the feeds don't go through your normal digestive system. You have PN through a central line or a PICC line.
A PICC line goes up a blood vessel in your arm and into a chest vein. Other types of central lines go into the chest and a major blood vessel, as this diagram shows:
How it works
The end of the line hangs out of the chest.
When it is not in use, a cap seals the central line. When you have your feed, a nurse removes the cap and connects the line to the drip containing your PN.
When all the feed has gone through, the nurse flushes the line. This is with either sterile salt water or an anticlotting solution. The nurse then seals the line again.
You usually have the line put in under local anaesthetic in outpatients. A specially trained nurse or doctor does this procedure. There can be complications. Sometimes lines get infected or blocked and have to be taken out and replaced.
When you might need it
You are only likely to need PN feeding when your gut is not working. For example, if you:
- have severe sickness
- have severe problems with your stomach or intestine, or if they have been removed
- have severe nutritional problems before surgery and can't have enteral feeding
- have a hole (fistula) in your stomach or oesophagus
- are losing a lot of weight or not coping well with enteral feeding
About PN feeds
The feeds used for PN are very complex. They are carefully made up in a sterile room each day by a pharmacist.
Doctors and dietitians tell the pharmacist about your specific nutritional needs each day. They will check you regularly while you have PN. You will need frequent blood tests to check that your blood is normal. These include your levels of potassium, sugar, sodium and other substances.
PN can have side effects. These include a high blood sugar level, or they may affect the way your liver works.
Your doctor gradually reduces your PN feeds when it is time for you to stop having them.
Giving food directly into the stomach or bowel
If you have a feed through a tube into your stomach or small intestine, it is called enteral nutrition.
Enteral nutrition uses specially prepared liquid feeds. Different formulas are available. Your dietitian chooses the most appropriate one for you. This depends on your own particular nutritional needs.
You might need to take all your food and drink this way. Or you may take some food by eating normally, and then have the rest as a liquid through the tube.
Enteral feeding is only for people whose stomach and intestines work as usual. This is because the feeds still go through the usual path of digestion.
Enteral feeding is not suitable if you have:
- a blockage in the bowel
- severe diarrhoea or sickness
The feeds are concentrated and can sometimes cause a bloated feeling and diarrhoea. If this happens, you might need to have your feeds at a slower rate. It is common to start off slowly and then build up the amount gradually.
You might also need extra fluids through a drip to prevent dehydration if you have diarrhoea.
Different types of tubes
There are a number of types of tubes used for enteral feeding:
A nasogastric tube is a thin tube that goes in through your nose and down your throat into your stomach. You might have this if you need feeding for less than 3 weeks.
A nurse or a doctor puts the tube in. It is not pleasant but is a quick procedure.
Some people might have a nasojejunal tube (NJT).
An NJT is like a nasogastric tube, but the tip goes into the second part of the bowel (the jejunum).
NJTs are used:
- when the stomach cannot empty properly
- to get past a blockage in the small bowel
- after pancreatic surgery
You might have this type of tube if you have had stomach or oesophageal surgery.
These tubes go into a part of the small intestine called the jejunum. The jejunum is situated a little way after the stomach.
To put a PEJ tube in you have an endoscopy. Your doctor gives you sedation. They put a tube with a camera on the end through your mouth, down your food pipe and into your stomach. This way they can see where to place the PEJ tube. The surgeon then puts the jejunostomy tube through an opening in the tummy (abdomen) and into your jejunum.
With a PEJ tube, you usually have feeds at a slow rate. You have a pump that controls the speed of the feed passing into the tube.
Some people might have a RIG tube. It is a gastrostomy tube. Your doctor puts it directly into your stomach under x-ray guidance.
You have it under local anaesthetic. It is for people who can't have an endoscopy. This might be because of a tumour in the oesophagus.
You might have a PEG tube if you have long-term problems with eating and swallowing. For example, with cancer of the head and neck or cancer of the oesophagus.
A PEG tube goes into your stomach through an opening made on the outside of your tummy (abdomen).
To put a PEG tube in you have an endoscopy. Your doctor gives you sedation. They put a tube with a camera on the end through your mouth, down your food pipe and into your stomach. This way they can see where to place the PEG tube. The surgeon then puts the tube through an opening in the tummy (abdomen) and into your stomach.
The feeds usually run for most of the day through a pump. You have a break of a few hours to give the stomach a rest. But sometimes feeds can go in over 24 hours at a low rate. If you have feeds at home, your dietitian will guide you about how much feed you need and the timings.
Tube feeding at home
You might need to go on using these methods of feeding after you leave hospital. This may seem scary at first, but people usually get the hang of it quickly. So try not to worry too much about it.
Your nurses show you and your carers how to run the feeds before you leave hospital. Most people have daily visits from a district nurse at first. These go on for as long as you need them. And your nurses give you the telephone numbers of people to contact if you need help.
You will have regular follow up appointments to check on how you are getting on.