Hemodialysis uses an artificial kidney, called a dialyzer, and a hemodialysis machine to filter your blood. During the treatment, a small volume of blood is pumped through a specially prepared tubing set to the dialyzer, where excess body water and waste products in the blood are removed. The cleaned blood is then returned to your body through the tubing set. There are only about 200 ml of blood outside the body at any one time during the treatment. Since the average adult has between 4–5 litres of blood, we can easily tolerate this small amount of blood outside of the body.
In order to gain access the bloodstream for dialysis, a surgeon will create one of three types of hemodialysis access:
A connection is made between an artery and a vein during a minor surgical procedure. Usually the surgeon will create the fistula at least one month before you start dialysis.
An artificial vessel (tube) is placed under the skin connecting an artery to a vein.
A temporary catheter is inserted into a vein. The catheter remains in place between treatments.
If you have a fistula or graft (usually in your arm), two fistula needles are inserted into the blood access to allow the blood to pass to and from the hemodialysis machine during the treatment. The fistula needles are removed when the treatment is finished. With a catheter, no needles are necessary for hemodialysis treatment, because the catheter is directly connected to the tubing system.
The time, length and frequency of hemodialysis (HD) treatment depends on medical issues, lifestyle and your dialysis unit. Treatments can be performed at a dialysis clinic or hospital (in-centre) or at home.
Medical staff will prepare, perform and monitor the treatment, which is usually performed three times a week for approximately 4–5 hours. Other things to be aware of:
- The dialysis machine and all required medical supplies are provided by the dialysis unit.
- A regular dialysis schedule is provided, e.g., Monday-Wednesday-Friday.
- You’ll need transportation from home to the dialysis unit and back.
- It's very important to always arrive on time for your treatment.
- You’ll have an opportunity to see and talk to other patients and medical staff.
At home you’ll prepare, perform and monitor the treatment yourself. Medical staff are able to offer support over telephone, if required. You’ll have more flexibility over the dialysis schedule and usually fewer fluid and dietary restrictions. Other things to be aware of:
- You (and, if required, a support person) will need to successfully complete a training program which usually takes 6–8 weeks.
- You will have a very flexible schedule and won't need regular transportation to and from dialysis unit. Treatment is often performed overnight while you sleep.
- A variety of alternative treatment options can be offered.
- The dialysis machine needs to be connected at home to the electrical circuit and water system, so electrical and plumbing outlets may need to be installed or modified. Energy and water consumption will increase.
- Sufficient space is needed for the hemodialysis machine, water treatment system and medical supplies.