Dialysis acts as an artificial kidney. There are two types of treatment: hemodialysis and peritoneal dialysis. About 90 percent
of
dialysis patients receive hemodialysis, in which the blood is circulated outside the body and cleaned inside a machine before
returning to the patient.
Before hemodialysis can be done, a doctor must make an entrance, called an access, into the patient's blood vessels. This is
done by minor surgery in the leg, arm or sometimes neck. The best access for most patients is called a fistula. Minor surgery is
performed to join an artery to a vein under the skin to make a larger vessel.
If no vessels are suitable for a fistula, the doctor might use a soft plastic tube called a vascular graft to join an artery and vein
under the skin. For temporary dialysis in the hospital, a patient might need a catheter implanted into a large vein in the neck.
Once the access is made and healed, two needles are inserted in the fistula or graft, one on the artery side and one on the vein
side.
Blood drains into the dialysis machine to be cleaned. The machine has two parts, one side for blood and one for a fluid called
dialysate. A thin, semi permeable membrane separates the two parts. As dialysate passes on one side of the membrane, and
blood on the other, particles of waste from the blood pass through microscopic holes in the membrane and are washed away in
the dialysate. Blood cells are too large to go through the membrane and are returned to the body.
The benefits of hemodialysis are that the patient requires no special training, and he or she is monitored regularly by someone
trained in providing dialysis.
This information was received from the Food and Drug Administration site: Please click on underlined word to receive more
valuable information on dialysis  and  why the mortality rate is so  high here.