Alternative Names artificial kidneys, peritoneal dialysis
Definition 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. Treatment is needed to replace the work of the failed kidneys. Once both kidney fail, a person will die without it. Dialysis is a way to keep a person with kidney failure alive.
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 haemodialysis, 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 haemodialysis, 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:
inside the body, usually in the arm
outside the body, usually in the neck
What happens right after the procedure? Usually, repeated dialysis is needed for survival. Most people who need dialysis have kidneys that are permanently damaged.
Peritoneal dialysis is done at home. After each time the equipment is used, it must be carefully cleaned. It is important to follow instructions to prevent infection.
Haemodialysis usually requires a person to go to a dialysis centre 3 times a week. People often feel tired, weak, and even confused after the first few sessions. Most of the time these sensations go away in a few weeks as the body adjusts.
What happens later at home? Home care is the objective of peritoneal dialysis. Following instructions and taking care of the equipment reduces problems.
People who use haemodialysis must take care of the fistula. The overlying skin should be kept clean and any harm to the area should be avoided. If the fistula is disturbed, further surgery may be needed.
What are the potential complications after the procedure? With peritoneal dialysis, the main complication is infection. Equipment should be kept clean to avoid this problem. The dialysis catheter may also stop working or a hernia may develop. These situations may require surgery to correct.
Haemodialysis patients often develop problems with the fistula, such as:
blood clots
infection
abnormal swelling of the site
Any of these problems may require further surgery.
During either type of dialysis, people may develop problems, such as:
low blood pressure
irregular heartbeats
infections
confusion
seizures
Author: Adam Brochert, MD Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request