Children having treatment for cancer will often need to have frequent blood tests. They also often need to have needles put into their veins so that chemotherapy and other drug treatments can be given. Even though doctors and nurses are very experienced at taking blood and inserting needles, it can sometimes hurt and is not a pleasant experience for your child.

For this reason, many children have a special tube called a central line (central venous catheter) put into a vein. The tube is used to take samples of blood and to give chemotherapy and other drugs (such as antibiotics). It can also be used to give blood or platelet transfusions.

A central line (central venous catheter) is a thin, flexible, plastic tube, which is inserted into a vein near the collar bone. It is put in under a general anaesthetic. The surgeon makes a small cut into a vein in the neck and feeds the tube down until the tip is in one of the large veins near to the heart. The other end of the tube is then tunnelled under the skin and comes out on the front of the chest.

A removable bung is attached to the end of the line, which allows samples of blood to be taken or medicines to be injected. It can also be used to give blood or platelet transfusions.

Instead of a tunnelled central line, your doctor may suggest that your child has a long, thin tube put into a vein in the crook of their arm. This is called a peripherally inserted central venous catheter (PICC). The doctor or chemotherapy nurse will explain the procedure to you. The line is put in under local or general anaesthetic.

Once in place, the PICC line is taped firmly to your child’s arm to prevent it being pulled out of the vein. It can stay in the vein for many months.

As with a tunnelled central line, having a PICC line means that your child does not need to have needles put into the vein to take blood or give chemotherapy. They will be able to bath or shower, although you should avoid water getting onto the area around the tube – a plastic dressing can be used for this.

Some tubes do not come out through the skin. Instead, they end in a reservoir or port that is under the skin below the collar bone. To give chemotherapy, or take blood, a small needle is pushed through the skin into the port. The skin over the port can be numbed with anaesthetic ‘magic’ cream (Ametop® or Emla cream®). This is done about half an hour before the port is used.

Before your child goes home, the nurses will show you how to care for the central line or port. Make sure that you feel confident about this and don’t be afraid to ask any questions. If you have any problems with the line when you are at home, contact the hospital staff.

Central lines can stay in place for many months and are a very good way of avoiding the discomfort of repeated injections. However, there are three main potential problems: falling out, blockage and infection.

Falling out  Rarely, a tube may fall out because a child pulls on the tube by accident when they are playing or asleep. Fortunately, if a tube does fall out, the blood clots quite quickly to seal up the wall of the vein. Some blood may ooze down the tunnel under the skin where the line was. However, the blood usually clots and seals off the tunnel very quickly. The hospital staff will tell you what to do if this happens.

Blockage  Occasionally, lines may seem to be blocked. This can be caused by the tip of the line lying at an odd angle against the wall of the vein. It can also be caused by the line becoming clogged up, even if it has been flushed with liquid regularly. If this happens, drugs can be put into the tube to dissolve the blockage so that the line can be used again. Your child may have a lineogram (a special scan which shows the position of the tube).

Infection  Despite being carefully looked after, some lines become infected. If infection occurs, antibiotics are given, but if these don’t clear the infection the line may need to be removed.