Dialysis is a treatment for kidney failure that removes waste and extra fluid from the blood, using a filter. In peritoneal dialysis (PD), the filter is the lining of the abdomen, called the peritoneum.
The following is an edited reprint of information compiled and created by the National Kidney and Urologic Diseases Information Clearinghouse, a service of the
National Institute of Health.
Peritoneal dialysis is another kidney dialysis procedure that removes wastes, chemicals, and extra water from your body. This type of dialysis uses the lining of your abdomen, or belly, to filter your blood. This lining is called the peritoneal membrane and acts as the artificial kidney.
How Peritoneal Dialysis Works
A mixture of minerals and sugar dissolved in water, called dialysis solution, travels through a dialysis catheter into your belly. The sugar—called dextrose—draws wastes, chemicals, and extra water from the tiny blood vessels in your peritoneal membrane into the dialysis solution. After several hours, the used solution is drained from your abdomen through the tube, taking the wastes from your blood with it. Then your abdomen is refilled with fresh dialysis solution, and the cycle is repeated. The process of draining and refilling is called an exchange.
Types of Peritoneal Dialysis
Three types of peritoneal dialysis are available.
- Continuous Ambulatory Peritoneal Dialysis (CAPD) – CAPD requires no machine and can be done in any clean, well-lit place. With CAPD, your blood is always being cleaned. The
dialysis solution passes from a plastic bag through the catheter and into your abdomen, where it stays for several hours with the catheter sealed. The time period that
dialysis solution is in your abdomen is called the dwell time. Next, you drain the
dialysis solution into an empty bag for disposal. You then refill your abdomen with fresh dialysis solution so the cleaning process can begin again. With CAPD, the
dialysis solution stays in your abdomen for a dwell time of 4 to 6 hours, or more. The process of draining the used
dialysis solution and replacing it with fresh solution takes about 30 to 40 minutes. Most people change the
dialysis solution at least four times a day and sleep with solution in their abdomens at night. With CAPD, it’s not necessary to wake up and perform
dialysis tasks during the night.
- Continuous Cycler-assisted Peritoneal Dialysis (CCPD)–CCPD uses a machine called a cycler to fill and empty your abdomen three to five times during the night while you sleep. In the morning, you begin one exchange with a dwell time that lasts the entire day. You may do an additional exchange in the middle of the afternoon without the cycler to increase the amount of waste removed and to reduce the amount of fluid left behind in your body.