Haemodialysis: central venous line

What is it?

A central venous line (or ‘line’) is a long, thin tube (catheter) that is placed into one of the large blood vessels in the body. This is usually in the neck or chest, or occasionally the groin. 

Part of the catheter is inside the body, and part outside. The part of the body where the catheter comes out is called the exit site

There are one or two ports, or caps, at the ends of the catheter, which connect to tubes for each dialysis session.

A line can be inserted shortly before the first dialysis session starts. 

Temporary line

A temporary line is used for short-term dialysis. The line is inserted by a surgeon/anaesthetist or nephrologist.  

The catheter is inserted into a vein, and exits in the same site.

Permanent line

A permanent line is used for long-term dialysis. The line is usually inserted by a surgeon or anaesthetist. 

The catheter is inserted in the vein and then tunnelled under the skin to exit at a different site. For example, if the catheter is inserted in the neck, it exits on the front of the chest. This means that the catheter cannot be seen when your child wears a shirt or blouse. It stays secure with a cuff, which sits under the skin. This type of catheter is sometimes called a tunnelled cuffed catheter.

Inserting a line 

A line can be inserted shortly before haemodialysis needs to start. The procedure takes place at your child’s paediatric renal unit, a specialised unit for babies, children and young people with kidney conditions, which may be in a different hospital.

The procedure usually takes 1-2 hours, though your child will probably stay in the hospital for at least one night to recover. You can bring a change of clothes and some toys and books. 

Preparing for surgery

Your child will be given a general anaesthetic, special medicine so he or she can sleep through the procedure and not feel any pain. The anaesthetist will speak to you about the best option for your child. You will be asked to give written consent, or permission, for the surgery.

Your child may be given antibiotic medicines to prevent infection.

What happens 

Your child will be moved into an operating theatre, a room where surgery takes place.

The general anaesthetic will be given as an injection or breathed in. When your child is asleep, the surgeon will make a small cut in the area where your child’s catheter will be inserted – this is normally in the chest or neck – and carefully place the catheter into a blood vessel.  

After the surgery

Your child will go back to the ward, where he or she will be monitored by a healthcare team – this may be for one or two days, or longer. He or she will have a dressing over the cut. The catheter will be taped to his or her skin.

Your child may feel some effects from the anaesthesia, but these do not usually last long. They include feeling sick and being sick (vomiting), headache, sore throat, or feeling dizzy or lightheaded.

Your nurse will give your child some medicines to help with any pain from the surgery.



All surgery has some risks, but these are very rare. Occasionally, children bleed from the cut. Some need to go back to the hospital, and/or will need to take antibiotic medicines to treat an infection. 

Very occasionally, the surgery causes a puncture wound in a lung. This may cause problems breathing (pneumothorax), and may require surgery to treat.


The most common complication is infection, caused by germs entering the body. Infections are more likely in a line than in a fistula. 

If your child has a fever (temperature above 38°C), this may be a sign of infection – contact your unit straight away.

Most infections can be treated with antibiotic medicines, which kill germs. 

Sometimes, this can be septicaemia (infection in the blood), which is more serious. In these cases, the line may need to be removed. A new line can normally be inserted after a few days, after the infection has cleared, and haemodialysis can start again.

Taking care of the line

You and your child will be shown how to keep the exit site clean to reduce the risk of infection, and to make sure the catheter stays taped to his or her body so it does not get dislodged or caught in clothing.

Make sure that you, your child or anyone else does not remove or touch the ends (the ports or caps) of the catheter. If this happens contact your renal unit.