Dialysis is a treatment for people in the later stage of chronic kidney disease (kidney failure). This treatment cleans the blood and removes wastes and excess water from the body. Normally, this work is done by healthy kidneys.

Sometimes dialysis is a temporary treatment. However, when the loss of kidney function is permanent (as in end-stage kidney failure), you must continue to have dialysis on a regular basis. The only other treatment for kidney failure is a kidney transplant.

There are two types of dialysis: hemodialysis and peritoneal dialysis. In hemodialysis, your blood is passed through an artificial kidney machine to clean it. Peritoneal dialysis uses a filtration process similar to hemodialysis, but the blood is cleaned inside your body rather than in a machine.

Hemodialysis means "cleaning the blood" - and that is exactly what this treatment does. Blood is circulated through a machine which contains a dialyzer (also called an artificial kidney). The dialyzer has two spaces separated by a thin membrane. Blood passes on one side of the membrane and dialysis fluid passes on the other. The wastes and excess water pass from the blood through the membrane into the dialysis fluid, which is then discarded. The cleaned blood is returned to your bloodstream.

HEMODIALYSIS MACHINE

You can be attached to the dialysis machine in different ways. The most common method of providing permanent access to the bloodstream for hemodialysis is an internal fistula in your arm. This involves having an artery and a vein connected surgically. When they are joined, the stronger blood flow from the artery causes the vein to become larger. Needles can be inserted in the enlarged vein to connect you to the dialysis machine.

Another way to provide access to the bloodstream is to insert an internal graft. In this procedure an artery is surgically connected to a vein with a short piece of special tubing placed under the skin. Needles can be inserted in this graft.

Sometimes, when it is necessary to gain access to the bloodstream quickly, or when the veins in the arms are too small to provide enough blood for hemodialysis, a central venous catheter is used. A soft tube is surgically inserted into a large vein in the neck or near the collarbone. This method is usually temporary until a permanent access site is ready.

Insertion of the needles causes pain, but only for a brief time. This can be difficult for some people. Occasionally nausea, muscle cramps or dizziness can occur due to the fast removal of extra water from your body, which may cause your blood pressure to drop.

Each hemodialysis treatment normally takes four to five hours, and usually three treatments a week are needed. More frequent, shorter treatments or longer treatments may be indicated for certain patients. Only a small amount of your blood is out of the body at one time. Therefore your blood must circulate through the machine many times before it is cleaned.

Hemodialysis may be done in a hospital dialysis unit, in a clinic away from the hospital, in a self-care centre (with some assistance from the staff), or at home. Special training is needed for self-care or home hemodialysis.

Many dialysis centres in Canada offer the option of training patients or their partners to carry out hemodialysis at home. The dialysis machine and necessary modifications to your home are provided by the hospital. While some home hemodialysis patients follow a standard schedule of four to five hours three days a week, some Canadian centres are also offering nocturnal home hemodialysis in which patients go on dialysis four to six nights a week for six to eight hours while they sleep. Nocturnal home hemodialysis greatly improves the removal of waste products from the body and has been found to improve well-being, allow for a more liberal diet and reduce the need for medications.

The type of dialysis treatment you receive depends on what is most appropriate for your particular needs. It may also depend on what is available in your community. Each type of dialysis has its strengths and limitations. Your healthcare team can provide information and support to help you understand all the options and answer any questions you or your family may have.

You will need to learn appropriate food choices to meet your nutritional needs and control the build-up of food wastes and water. Your dietitian will work with you to design an individual eating plan that is healthy and enjoyable. Medications and vitamins may also be prescribed.

You will need to plan your week around your hemodialysis schedule. You may have to take time off work or school before you start hemodialysis and when the treatments begin. However, once your health is more stable, you should be able to return to your normal activities. Depending on your energy level, you may have to make some adjustments in your work situation or limit your activities.

There are dialysis units across Canada and in many parts of the world. They have suitable facilities for visitors who need hemodialysis treatment. However, it is necessary to plan several months in advance due to limited space and staff. Your dialysis unit and local Kidney Foundation office can provide more information and advise you about travel costs and arrangements.

© 2004