Dialysis is a procedure that cleans and filters the blood when the kidneys are not working. Healthy kidneys clean the blood by filtering out extra water and waste products. When the kidneys fail, the body holds fluid and harmful wastes build up.
Who is a candidate for the procedure?
Dialysis is used to treat people with kidney failure, known as acute renal failure or chronic renal failure. Treatment is needed to replace the work of the failed kidneys. Once both kidneys fail, a person will die as a result of not having the filtering process. Dialysis is way to keep a person with kidney failure alive. A person waiting for a kidney transplant would be a candidate for dialysis.
How is the procedure performed?
There are two main ways to filter the blood:
In peritoneal dialysis, a special tube is put into the abdomen through the skin. A cleansing solution called dialysate travels through the tube into the abdomen. After several hours, the fluid gets drained from the abdomen. It takes wastes from the blood with it. This process may be repeated several times a day. Or it can be done during the night while the person sleeps.
In hemodialysis, blood is filtered using a special dialysis machine. Blood removed from the body through a blood vessel travels through tubes into the dialysis machine. The machine filters out wastes and extra fluids. The newly cleaned blood flows through another set of tubes and back into the body.
Both types of dialysis require surgery to prepare the person's body:
For peritoneal dialysis, a surgeon places a small, soft tube called a catheter into the abdomen. This tube stays in place.
For hemodialysis, the surgeon creates new access to the bloodstream called a fistula. This provides a way for blood to be carried from the body to the dialysis machine.
The access may be either inside the body, usually in the arm, or outside the body, usually in the neck.