For some years now doctors have been using central lines for some people who are going to have chemotherapy that would normally require a lot of injections and blood tests.

A central line is a thin flexible silicone tube, the tip of which is placed in one of the large veins deep in the chest (the superior vena cava). The line is put in under either a local or a general anaesthetic. The outside end of the line is on the chest, just above one or other nipple. It then tracks under the skin for a little way before going into a large vein just behind the collar bone. From there it goes into the superior vena cava.

A PICC line is a more recent development using a line which is inserted into one of the large veins in the arm (usually near the bend of the elbow) from where it is threaded into the superior vena cava. The initials PICC stand for peripherally inserted central catheter.

PICC lines are normally inserted as an outpatient. Some local anaesthetic cream is applied to the skin which usually ensures the insertion is painless. The procedure takes about 30 to 40 minutes. Once the PICC line is in place it will be taped firmly to the skin with a special transparent dressing to stop it coming out of the vein. A chest x-ray will then be taken to check the position of the line before it is used.

The PICC line can be used for taking blood for blood tests, giving chemotherapy drugs or giving blood transfusions.

Once the line is in place nurses will show you how to take care of it, to prevent any blockages or infections. This will involve learning how to clean the external part of the line, change the dressings and flush the line through with sterile salt solution. This may sound complicated at first but the nurses will explain it all and make sure you are able to cope. They will also give you a contact 'phone number at the hospital in case you have any problems.