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 a 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 (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.
- Combination of CAPD and CCPD – If you weigh more than 175 pounds or if your peritoneum filters wastes slowly, you may need a combination of CAPD and CCPD to get the right dialysis dose. For example, some people use a cycler at night but also perform one exchange during the day. Others do four exchanges during the day and use a minicycler to perform one or more exchanges during the night. You’ll work with your health care team to determine the best schedule for you.
Before your first treatment, a surgeon places a catheter into your abdomen or chest. The catheter tends to work better if there is adequate time—usually from 10 days to 2 or 3 weeks—for the insertion site to heal. Planning your dialysis access can improve treatment success. This catheter stays there permanently to help transport the dialysis solution to and from your abdomen.
Who Performs Peritoneal Dialysis
Both types of peritoneal dialysis are usually performed by the patient without help from a partner. CAPD is a form of self-treatment that needs no machine. However, with CCPD, you need a machine to drain and refill your abdomen.
The most common problem with peritoneal dialysis is peritonitis, a serious abdominal infection. This infection can occur if the opening where the catheter enters your body becomes infected or if contamination occurs as the catheter is connected or disconnected from the bags. Infection is less common in catheters, which are placed in the chest. Peritonitis requires antibiotic treatment by your doctor.
To avoid peritonitis, you must be careful to follow procedures exactly and learn to recognize the early signs of peritonitis, which include fever, unusual color or cloudiness of the used fluid, and redness or pain around the catheter. Report these signs to your doctor or dialysis nurse immediately so that peritonitis can be treated quickly to avoid additional problems.