Types of nutritional support

The two main types of feeding system are:

  • enteral nutrition (EN)
  • parenteral nutrition (PN).

Enteral nutrition (EN) is when nutritional fluid is given through a tube going into the stomach or small intestine. It may be given when the digestive system is working well, but you have problems eating enough.

If you only need nutritional support for a short time, the tube may be passed through the nose down into the stomach. If nutritional support is likely to be needed for more than a few weeks, a tube is passed through the skin and muscle of your abdomen straight into the stomach or small bowel.

Parenteral nutrition (PN) is giving nutrients and fluid directly into the bloodstream through a tube going into a vein in the neck, chest or arm. It is sometimes called total parenteral nutrition. It is usually only used for short periods of time.

There are some other types of feeding options. Your doctor will decide which feeding system is best for you based on your individual circumstances.

Types of nutritional support

There are two main types of nutritional support. We explain them here.

Enteral nutrition (EN)

This is where the nutritional fluid or feed is given into the gut, through a tube going into the stomach or small intestine. This is often called tube feeding.

EN works best if your digestive system is working normally but you are not able to eat or drink enough, for example because of a cancer in the head or neck area.

There are several ways of giving EN. These are the most common:

  • Nasogastric feeding (NG feeding) – a thin tube is passed down the nose and into the stomach.
  • Percutaneous endoscopic gastrostomy (PEG feeding) and radiologically inserted gastrostomy feeding (RIG feeding) – a tube is passed through the skin and muscle of the tummy (abdomen) into the stomach.
  • Percutaneous endoscopic jejunostomy feeding (PEJ feeding) – a tube is passed through the skin and muscle of the tummy (abdomen) into the middle of the small bowel (the jejunum) just below the stomach.

Tube feeding through NG, PEG or RIG is often used after surgery to the head, neck, stomach or gullet (oesophagus). There can be other reasons for using feeding tubes.

Parenteral nutrition (PN)

This is where the nutritional fluid is given through a tube that is put into a vein (intravenously). PN gives nutritional support when you can’t take nutrients in through your digestive system.

PN is usually used if people are unable to have EN, for example if a person has had surgery on the small bowel or has a bowel obstruction. It may also be used if it is difficult to insert the tubes used for EN. This can happen after some types of surgery to the head, neck or stomach.

Nasogastric (NG) feeding

Nasogastric feeding is usually recommended if you are likely to need nutritional support for only a short time (usually less than a month). NG feeding may also be used for people having radiotherapy to the mouth, throat or gullet (oesophagus) if swallowing becomes difficult because of swelling or other side effects of treatment.

How an NG tube is put in

You need to be in a comfortable position, sitting upright. A thin, flexible tube is gently inserted into your nostril, down the back of the throat, down the gullet (oesophagus) and into your stomach. A local anaesthetic may be sprayed into the nostril to make it more comfortable when it is put in.

It is important that the person inserting the NG tube checks it is correctly positioned in your stomach. They do this by drawing some fluid out from the tube using a syringe. Because stomach fluid is very acidic, fluid drawn out from the tube is tested for acidity with a pH indicator to show if the tube is in the stomach. Sometimes you need an x-ray to make sure the tube is correctly placed in the stomach.

Once the tube is correctly positioned, it will be taped to your nose or cheek to keep it in place.

Nasogastric tube
Nasogastric tube

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Your dietitian will work out how much liquid feed you need to have each day. The hospital staff will give this to you through the tube. If you are at home, the liquid feed can be prescribed by your GP, who will ask your local pharmacy to supply it for you. You or your carer will be shown how to give the liquid feed. A district nurse might also visit you.

Other fluids, such as liquid medicines, can also be given through the tube. They need to be flushed through with plenty of water so they do not block the tube. Your dietitian, doctor, nurse or pharmacist can show you how to do this. They can also tell you which medicines you can have this way.

Possible problems with NG feeding

There can be disadvantages and possible complications with any type of nutritional support. With NG feeding, these could include the following:

  • When the NG tube is put in, you may find it uncomfortable and quite distressing. It can be done very quickly, but it can sometimes take more than one attempt to get the tube into the right place.
  • The end of the tube comes out through the nostril and is taped to your face. Some people may find this embarrassing and feel self-conscious about it.
  • If they are not fixed securely, NG tubes can come out of the stomach. Occasionally the tube can move and the tip enters the lungs. Before each time the tube is used, the position of the tube must be checked. Normally, some fluid is drawn out of the tube and checked for the level of acidity (pH level). In hospital, the nurses will do this or they will show you how to do it. If you are at home, you or your carer will need to do this before each feed, water flush or medication. If the pH levels suggest the tube is not in the stomach, the tube must not be used. It may need to be removed and replaced.
  • Sometimes the tube may fall out completely and need to be replaced. If you are at home, you will have contact numbers of health professionals who you can call if this happens, for example your specialist doctor, nurse, dietitian or pharmacist.
  • NG tubes can sometimes become blocked. Water is flushed down the tube regularly to try to prevent this from happening. But if a blockage occurs and can’t be cleared, the tube will need to be removed and a new one put in.
  • An NG feed can be inconvenient, as the liquid feed often needs to be given slowly into the tube over several hours. Some people prefer their feed to be given overnight, so that they are not restricted during the day. Your dietitian will talk to you about the best way of giving the feed, so that it does not interfere too much with your lifestyle. It may be possible to use a small pump you can carry around with you.
  • NG tube feeding usually works well, but some people may experience reflux. This is where feed flows up into the gullet, which can be unpleasant and may make you feel sick. Medicines can be given to control this, so let your doctor know if this happens.

Percutaneous endoscopic gastrostomy feeding (PEG feeding) and radiologically inserted gastrostomy feeding (RIG feeding)

Gastrostomy feeding is recommended if your digestive system is still working well but you may need nutritional support for more than a few weeks.

Gastrostomy feeding is when an opening, called a fistula, is made through the abdominal wall. A feeding tube is then passed through the opening into the stomach.

The feeding tube is held in place with a small inflated balloon around the tube just under the skin, or a flange around the tube just under the skin.

How a PEG is put in

Before a PEG is put in, a doctor or specialist nurse will explain the procedure to you. You will be asked to sign a form saying that you agree (consent) to having the PEG put in, and that you understand why it is being done.

You will not be able to eat or drink for several hours before the procedure, to make sure your stomach is empty. Your doctor may also give you antibiotics to reduce your risk of getting an infection.

You will be given a sedative to make you feel sleepy. The person putting the PEG in will pass a flexible tube with a light at the end (an endoscope) into your mouth, down the gullet and into the stomach. They will inflate the stomach with air, and position the endoscope so that the light at the end shines through the abdominal wall to show the position of the stomach.

The person doing the procedure will clean the skin of the abdominal wall and use local anaesthetic to numb the area. They will make a small cut through the skin and muscle and then insert the feeding tube into the stomach.

Once the tube is in place, the area around the tube (the tube site) is cleaned. The area around the tube needs to be cleaned daily with soap and water and thoroughly dried. You may need a dressing at first, but the area is then usually left open to the air. The tube needs to be flushed with a minimum of 30ml of water before and after each feed.

It takes about three weeks for the skin to heal around the tube. During this time, you should avoid getting the area too wet. It is fine to shower, as long as the exit site is protected. It is also fine to wash, but you should avoid having a bath until the skin is fully healed.

Your dietitian will explain how much liquid feed you need to have through the tube each day.

How a RIG is put in

A RIG is put in in a similar way to a PEG, but x-ray scanning is used to guide it rather than an endoscope. An NG tube is put in first (see above). You will then have some local anaesthetic injected to numb an area on your tummy (abdomen) before a small cut (incision) is made.

Some air is pumped down the NG tube and into the stomach. This helps position the RIG tube accurately. The gastrostomy tube is then put directly into the stomach using x-ray guidance.

Once the gastrostomy tube is in place, some dye is flushed into it and an x-ray is taken to make sure it is in the right place. After this, the NG tube is removed. The RIG is held in place with stitches, which are usually removed about ten days later. 

Percutaneous endoscopic gastrostomy
Percutaneous endoscopic gastrostomy

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Benefits of PEG or RIG feeding

PEGs and RIGs allow people who can't eat in the usual way to take in enough nutrients through the liquid feed and fluids. These tubes can't be seen when a person is wearing clothes, whereas a nasogastric (NG) tube can be.

Possible problems with PEG or RIG feeding

The most common complications with a PEG or RIG include the following:

  • A blockage can develop in the tube. Flushing the tube before and after each feed reduces the chance of this happening.
  • The feed needs to be given slowly, and this can restrict you from moving around freely. Many people prefer to have their feed overnight. Your dietitian can discuss this with you, so that you can get on with your daily life as much as possible.
  • If the feed is given too quickly, some people may feel sick or have a sensation of stomach contents flowing back up the gullet (reflux). Let your doctor know if this happens, as they can give you medicines to help.
  • Infection can develop in the tissues around the site. It is important to tell your doctor as soon as possible if:
    • the skin around the tube becomes red or swollen
    • you notice discoloured fluid coming from around the tube
    • you develop a high temperature or feel unwell.

Rarely, more serious complications may develop. Contact your hospital straight away if you: 

  • develop any swelling around your tummy area 
  • have pain 
  • are bleeding 
  • start to feel very unwell. 

If you are at home, you should be given the name of a healthcare professional at the hospital to contact if you develop any problem with your PEG or RIG.

PEGs or RIGs can stay in place for up to two years, but many people have them for much shorter periods. After this, they can be replaced if they are still needed.

Percutaneous endoscopic jejunostomy feeding (PEJ feeding)

Some people may have a percutaneous endoscopic jejunostomy (PEJ). This is also called a surgical jejunostomy (JEJ).

This procedure is similar to a PEG or RIG, but the tube is passed into the middle part of the small bowel, called the jejunum, instead of the stomach. A PEJ may also be inserted at the same time as surgery to the gullet or stomach.

Caring for and possible problems with a PEJ are the same as for PEG or RIG tubes. But a PEJ tube feed needs to be given more slowly, and the water put into the PEJ needs to be sterile, or boiled then cooled.

Parenteral nutrition (PN) or total parenteral nutrition (TPN)

Parenteral nutrition (PN) means giving nutrients and fluid directly into the bloodstream. PN is sometimes referred to as TPN, which means total parenteral nutrition. However, as it is not always possible to provide total nutrition through the bloodstream, TPN is more commonly known as PN.

How PN is given

PN is usually given through a thin tube, which is inserted into a large vein in your neck or chest. The tube is called a central line. Sometimes it is given through a thin tube in your arm that goes up into a vein in your chest. This is called a PICC line (peripherally inserted central catheter).

Occasionally, a vein in the arm may be used (like having an ordinary drip), but this is less common. It tends to be used if feeding is only needed for a short time (less than 10 days) and if you are not on restricted fluids, as fluids need to be more diluted if an arm vein is used.

The doctors will decide the best type of feeding for you.

How the central line or PICC line is put in

Your central line or PICC line will be put in at the hospital by a specially trained nurse or doctor. A central line can be put in under a local or general anaesthetic. A PICC line is put in using a local anaesthetic.

You will have an x-ray to make sure that the tube is in the right place. You should not feel any pain when the tube is being put in, but you may feel a bit sore for a few days afterwards. A mild painkiller such as paracetamol will help ease this.

Benefits of PN

PN can give you nutrition even when the digestive tract is not working. It can allow the digestive tract to rest so that it can heal, for example after surgery to the stomach or bowel. It can also be used if you are experiencing severe vomiting, diarrhoea or a sore mouth, and cannot have enteral feeding.

Possible problems with PN

It is possible for an infection to develop either inside the line or around the exit site. You should tell your doctor if:

  • the exit site becomes red or swollen
  • you notice discoloured fluid coming from it
  • you develop a high temperature (fever) or feel unwell.

You may be given antibiotics or, if the infection is serious, the tube may have to be removed.

It is possible for a blood clot (thrombosis) to form in your vein at the tip of the central line. If this happens, the tube may have to be removed. You may be given some anti-clotting medicines to prevent this from happening. The medicines are usually added to the feed.

You will have regular blood tests while having PN. This is to check that your levels of sugar, minerals and other substances are normal. PN can sometimes change your blood sugar levels and you may need insulin to control your blood sugar level if it is too high. Your feed will be specially prepared for you each day according to your blood sugar levels and nutritional needs.

PN is usually started slowly. Your feed will be reduced over a few days when you no longer need it.

Home feeding

Many people can have nutritional support at home. Having PN is more difficult to deal with than NG or PEG feeding. You may need to be referred to a specialist hospital to be shown how to manage the PN feeds at home.

The thought of having nutritional support at home may make you feel anxious. Before you are discharged from hospital, you will be shown how to manage your feeding system. If you have a carer, they will be shown too.

Home nutritional support will not start until you, and your carer if you have one, feel confident in dealing with the tube and the feeds.

A team of healthcare professionals will also help to support you at home. The support offered to people may vary, but your GP, district nurse and dietitian can help you.

Some NHS trusts work in partnership with specialist home-care companies to make sure people who go from hospital care to home care have the support they need.

Your feelings

Many people feel upset if they need nutritional support or cannot eat or drink as they normally would. You may find having enteral feeding such as an NG tube or a PEG affects how you feel about your body image. These are all normal reactions. It is part of the process many people go through in trying to come to terms with their condition.

Everyone has their own way of coping with difficult situations. It may be helpful to talk to your doctor, specialist nurse or dietitian about how you feel. Some people find it helpful to talk to family or friends. Others prefer to get help from people outside their situation. Some may prefer to keep their feelings to themselves. There is no right or wrong way of coping, but help is available if you need it. You may want to contact our cancer support specialists for information about counselling in your area.