Nutritional support and cancer

Malnutrition and weight loss can occur as a result of cancer or cancer treatments. Many people with cancer may have a reduced appetite or difficulty in swallowing. These problems may only occur for a short time, or may be overcome with dietary supplements such as nutritious drinks. However, some people with cancer may find that nutritious drinks are not enough to maintain their weight or that their cancer may cause problems with swallowing.

If you are not able to eat or drink enough to maintain your weight your doctors may feel that it is necessary to start nutritional support. This may seem a very daunting prospect.

Nutritional support is used to help people who are not able to eat or drink normally. It can:

• prevent weight loss
• help people who need to build themselves up to put on weight
• give liquid food to overcome weakness or tiredness
• make sure that people take in enough liquid
• ease the pressure of having to eat: for example, if people have problems swallowing and find it difficult to eat

Why nutritional support is used

Generally, nutritional support is needed:

• if a person has difficulty swallowing (for example due to cancer of the throat or gullet)
• if a person has an unintentional weight loss (usually of 10% or more of their body weight) which is not helped by dietary supplements
• or if a person has been unable to eat or drink enough for a period of time, and having dietary supplements has not helped.

Types of artificial feeding

Two main types of feeding systems are used. These are known as Enteral Nutrition (EN) and Parenteral Nutrition (PN).

• Enteral nutrition is where the nutritional fluid is given into the gut through a tube going into the stomach or small intestine.
• Parenteral nutrition is where a tube is put into a vein and the nutritional fluid is given through this. PN is sometimes called TPN (total parenteral nutrition) as this aims to give total nutritional support, but this is not always possible.

The type of nutritional support you might have

The type of nutritional support you will have depends on a number of factors:

• Enteral nutrition is best for you if your digestive system is working normally, but for some reason you are not able to eat enough, for example, due to a cancer in the head or neck area.
• Parenteral nutrition (nutrition into the vein) is usually used if people are unable to have EN: for example, if you have had major surgery on the small bowel; have a bowel obstruction; or if the insertion of the tubes used for EN would be difficult, such as after some types of surgery to the head, neck or stomach.

Enteral nutrition (EN)

There are several ways of giving EN. The most common methods used are:

• nasogastric (NG) feeding, in which a thin tube is passed down the nose and into the stomach
• percutaneous endoscopic gasrostomy (PEG) feeding in which a tube is passed into the stomach, through the skin and muscle of the abdomen
• percutaneous endoscopic jejunostomy (PEJ)  Less commonly, a feeding tube is passed into the top part of the small bowel (the jejunum) just below the stomach, and this is known as a jejunostomy.

Nutritional support through a nasogastric tube or a gastrostomy is often used after surgery to the head, neck, stomach or gullet (oesophagus).
 

Nasogastric (NG) feeding

Nasogastric feeding is usually recommended if you are likely to need to be given nutritional support for only a short time. NG feeding may also be used for people having radiotherapy to the mouth, throat or gullet, if swallowing becomes difficult due to swelling from the radiotherapy.

How an NG tube is put in

You will 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. It is important that the person inserting the NG tube checks that it is correctly positioned in your stomach.

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

Your dietitian will work out how much liquid food you need to have each day and you can be given this through the tube by the hospital staff. If you are at home, the liquid food can be prescribed by your GP, who will ask your local pharmacy to supply it for you.

Other fluids, such as liquid medicines, can be given through the tube. Your dietitian, doctor, nurses or pharmacist can advise you about which medicines can be given through the tube. They will show you how to give them properly. Medicines can block the tube if they are not diluted properly and flushed through with plenty of liquid.

Possible problems with NG feeding

There can be drawbacks and possible complications with any type of nutritional support. With NG feeding the main drawbacks are as follows:

• You may find the insertion of an NG tube uncomfortable and possibly quite distressing. The procedure is usually completed very quickly, although sometimes it can take more than one attempt to get the tube into the right place.
• As the end of the tube comes out through the nostril and is taped to the face it is obviously visible. You may find this embarrassing and might feel self-conscious about it.
• NG tubes can be pulled out of the stomach if they are not fixed securely. Before each feed the position of the tube needs to be checked. In hospital the nurses will do this or will show you how to do it. Normally, some fluid is drawn out of the tube and checked with a pH indicator. If you are at home, you, or a member of your family, will need to do this before each feed.
• Occasionally the tube may become dislodged. This can result in the tip of the tube entering the lungs, in which case it will need to be removed and replaced. Sometimes the tube may fall out completely and will then need to be replaced.
• NG tubes can sometimes become blocked. To try and prevent this from happening, water is flushed down the tube at regular intervals. However if a blockage occurs and cannot be cleared the tube will need to be removed and a new one put in.
• An NG feed can be inconvenient, as the liquid food often needs to be given slowly into the tube over a number of hours and during this time you will not be able to move around freely. Some people prefer to have their feed 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 suitable to use a small portable pump to regulate the flow of the feed.
• If the feed is given too quickly it can flow up into the gullet, which can be very unpleasant and may make you feel sick. Medicines can be given to control this, so let your doctor know.

Percutaneous Endoscopic Gastrostomy (PEG)

PEG feeding is recommended if your digestive system is still working well but nutritional support is likely to be needed for more than a few weeks. It may be used for people whose cancer is blocking the gullet and so nasogastric feeding cannot be used.

PEG feeding involves surgically creating an opening, known as a fistula, through the abdominal wall. A feeding tube can then be passed through the opening and into the stomach. The feeding tube is held in place with either a stitch, 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, the procedure will be explained to you by a doctor or specialist nurse. You will be asked to sign a consent form to say that you agree to having the PEG put in and that you understand why it is being done.

You will need to have nothing to eat or drink for 6–8 hours before the procedure, to make sure that your stomach is empty. You will be given antibiotics and will be asked to use an antiseptic mouthwash to reduce the risk of any infection developing.

You will be given a sedative to make you feel sleepy. A flexible tube with a light at the end (an endoscope) is passed into your mouth, down your gullet and then into the stomach. The stomach is inflated with air and the endoscope is positioned so that the light at the end shines through the abdominal wall to show the position of the stomach.

The skin of the abdominal wall is then cleaned and a local anaesthetic is used to numb the area. A small cut is made through the skin and muscle through which a feeding tube is inserted into the stomach.

Following the procedure the area around the tube (known as the tube site) is cleaned. A dressing is not usually necessary unless there is leakage of fluid from the site. The area around the tube needs to be cleaned daily with soap and water and thoroughly dried. The tube needs to be flushed with 30mls of water before and after each feed. It takes approximately three weeks for the skin to heal around the tube, and during this time it is recommended that you do not get the area wet. It is fine to shower as long as the exit site is protected. It is also fine to wash, but bathing should be avoided. 

Advantages of PEG feeding

• PEGs enable people who cannot eat normally to take in enough liquid food and fluids.
• The tube cannot be seen when people are fully clothed, and so this method of nutritional support is more discreet than a nasogastric tube.

Possible problems with PEG feeding

The most common complications of a PEG tube include:

• a blockage developing within the tube. Flushing the tube before and after each feed reduces the chance of blockage.
• infection developing in the tissues around the site. It is important to tell your doctor 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

Some people may have a sensation of stomach contents flowing back up the gullet (known as reflux), or nausea, if the feed is given too quickly. Let your doctor know if this happens, as medicines can be given to help.

As with NG feeding, the feed needs to be given slowly and this can restrict you from being able to move around freely. For this reason many people prefer to have their feed overnight. Your dietitian can discuss your feeding with you, so that you can minimise the disruption to your daily life.

If you are at home, you should be given the name of a health professional at the hospital so that you can contact them if you develop any problem with your PEG tube.

PEG tubes can remain in place for approximately two years. After this time they can be replaced if they are still needed.
 

Jejunostomies

Some people may have a Percutaneous Endoscopic Jejunostomy (PEJ). This procedure is similar to a PEG, but a feeding tube is passed into the middle part of the small bowel (the jejunum) instead of the stomach. A jejunostomy may be inserted at the same time as surgery to the gullet or the stomach.

The care and issues are the same as for PEG tubes, but a PEJ feed needs to be given very slowly, and any water put into the PEJ needs to be sterile or boiled.

Parenteral nutrition (or total parenteral nutrition)

Parenteral Nutrition (PN) means giving necessary nutrients and fluid directly into the blood stream. Total parenteral nutrition (TPN) aims to give complete nutrition into the bloodstream: in other words, every nutrient that the body needs. It is very difficult to achieve total parenteral nutrition.

Advantages of parenteral nutrition

PN allows nutrition to be given 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.

A thin tube is inserted into a large vein in your neck or chest. The tube is also known as a central line. Occasionally a vein in the arm may be used - this is known as a peripheral line.

Sometimes a vein in the arm may be used but this is less common. It tends to be used if feeding is only necessary for a short period of time (less than 10 days) and if you are not on restricted fluids, as fluids need to be more dilute if an arm vein is used. An arm vein may be used for children who need nutritional support.

The doctors will decide which is the best type of feeding for your particular situation taking into account your individual circumstances.

How is the TPN/PN central line put in?

Your central line will be put in at the hospital by a doctor. It is usually put in under a general anaesthetic, but sometimes a local anaesthetic may be used. 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.

First, your chest is cleaned with an antiseptic solution. A small cut is made in the skin near your collarbone and the tip of the tube is threaded into a large vein. This is called the insertion site. The tube is then tunnelled under the skin to reach the exit site. The exit site is the place where the end of the tube comes out of your body. You will have an x-ray to make sure that the tube is in the right place.
 

When the tube has been put in you will have dressings covering the insertion and exit sites. You may have some pain or discomfort where the tube has been tunnelled under the skin. A mild painkiller such as paracetamol will help to ease this.

The line is kept in place with a stitch.

Possible problems with TPN

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 temperature

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.

Your dietitian and pharmacist will create a feeding plan that, as far as possible, contains the nutrients in a normal diet and takes into account your individual needs.
 

Home feeding

Many people can have their nutritional support at home. Having parenteral nutrition may be more difficult to deal with than nasogastric feeding or PEG feeding and you may need to be referred to a specialist cancer hospital to be shown how to manage the parenteral feeds at home.

The thought of having nutritional support at home away from the controlled environment of the hospital may make you feel very anxious. Before you are discharged home from hospital, you and your carers should be given extensive training in how to manage your particular feeding system. Home nutritional support will not start until everyone involved feels confident in dealing with the tube and the feeds.

A team of health professionals will also be involved in supporting 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 ensure that people who go from hospital care to home care receive the support and expertise that is needed.