There are two common forms of access:
AV (arterio-venous) fistula
- Created surgically at least six weeks before haemodialysis needs to begin. It is done under a local or a general anaesthetic.
- Creating a fistula involves joining a vein to an artery, usually in the upper arm or wrist, to gradually form a bigger, stronger blood vessel. This makes it easier to insert the needles that are required to withdraw blood and then return it to the body.
- Patients who have a fistula can usually feel it "buzzing" slightly. This is a good sign - it means that it's working well. If it stops buzzing, you should let your Renal Unit know, as this may be an indication that the blood has clotted.
- Some people have more of a problem with clotting than others, and have difficulty keeping their fistula open. These patients may be given an artificial fistula called a graft, in which a tube made from special material or a vein is sewn in place to join the artery and vein.
- Once a fistula is established, it is likely to cause few problems. In some cases, however, a fistula may be created too big or too small, and will need to be corrected.
Another form of access to the blood for dialysis is a neck line (also sometimes called a haemocath).
This is a narrow tube which is inserted into the vein between the shoulder and the neck.
The tube is closed off when not in use, with a short length of double tube - for taking and returning blood - left outside of the skin.
- With this kind of access, you don't have to wait several weeks for the vein to grow (like you do with a fistula), so it can be used when a patient needs to start dialysis right away. It is often used on a temporary basis, until a fistula has been established.
About the needles...
There's no getting away from the fact that haemodialysis involves inserting needles. However, the type of needles that are put into a fistula are so thin that most patients find them to be almost painless. People who are particularly sensitive can have a local anaesthetic gel rubbed onto the skin first.
The first few times a needle is inserted into a new fistula are likely to be the most difficult, and may cause some bruising - but it really does get easier very quickly. If you have steady hands and good eyesight, you may be able to learn to needle yourself.
For people who are overwhelmed with fear (have a phobia) about needles, the prospect of dialysis may seem like a nightmare. Phobias can, however, be significantly reduced or even totally cured with the help of a trained psychologist.
Trusting your blood to a machine
The actual filtering of the blood is done by the dialyser, which is actually quite a small part of the equipment involved.
The dialyser is hooked up to a machine that performs a number of functions, including a series of automatic checks to monitor the system and make sure it is operating safely, in particular that there are no leaks of blood or air.