In peritoneal dialysis, a sterile cleansing solution (dialysate) flows through the catheter into your abdomen. The solution stays in your abdomen for a prescribed period of time, known as dwell time. During this dwell time, waste, chemicals and extra fluid in your blood pass from tiny blood vessels (capillaries) in the lining of your abdominal cavity (peritoneum) into the dialysis solution. The solution contains a sugar that draws wastes and extra fluid through the capillaries in your peritoneum into your abdomen. Your belly may feel fuller than usual while the dialysis solution is there, but it's generally not uncomfortable.
When the dwell time is over, the solution, along with waste products drawn from your blood and any excess fluid, drains into a sterile collection bag. The process of filling and then draining your abdomen is called an exchange.
Different methods of peritoneal dialysis have different schedules of daily exchanges. The two main schedules are continuous ambulatory peritoneal dialysis (CAPD) and continuous cycling peritoneal dialysis (CCPD). Some people use a combination of both methods.
Continuous ambulatory peritoneal dialysis (CAPD)
With this form of peritoneal dialysis, you fill your abdomen with dialysis solution and later drain the fluid. Gravity moves the fluid through the tube and into and out of your belly.
Each exchange includes filling your abdomen with dialysate fluid, letting the fluid dwell in your abdomen, then draining the fluid. You may need three to four exchanges during the day and one with a longer dwell time while you sleep. You can do the exchanges at home, work or any clean place. You're free to go about your normal activities while the dialysis solution dwells in your abdomen between exchanges.
Continuous cycling peritoneal dialysis (CCPD)
With CCPD, which may also be called automated peritoneal dialysis (APD), a machine called an automated cycler performs three to five exchanges at night while you sleep. The cycler automatically fills your abdomen with dialysis solution, allows it to dwell there and then drains it to a sterile drainage bag that you empty in the morning. This gives you more flexibility during the day, but you must remain attached to the machine for 10 to 12 hours at night. In the morning, you begin one exchange with a dwell time that lasts the entire day. You're not connected to the machine during the day.
Which form of peritoneal dialysis is best for you depends on your lifestyle, personal preferences and medical condition. You may also customize your program by combining the two forms. For instance, if you're using CCPD, you may do one extra exchange in the afternoon to remove more waste and prevent absorption of too much fluid.
May. 21, 2013
- Peritoneal dialysis: What you need to know. National Kidney Foundation. http://kidney.niddk.nih.gov/kudiseases/pubs/peritoneal/. Accessed April 16, 2013.
- Papadakis MA, et al. Current Medical Diagnosis & Treatment 2013. 52nd ed. New York, N.Y.: The McGraw-Hill Companies; 2013. http://www.accessmedicine.com/resourceTOC.aspx?resourceID=1. Accessed April 16, 2013.
- Chaudhary K, et al. Peritoneal dialysis first: Rationale. Clinical Journal of the American Society of Nephrology. 2011;6:447.
- Longo DL, et al. Harrison's Online. 18th ed. New York, N.Y.: The McGraw-Hill Companies; 2012. http://www.accessmedicine.com/resourceTOC.aspx?resourceID=4. Accessed April 16, 2013.
- Post TW, et al. Overview of the management of chronic kidney disease in adults. http://www.uptodate.com/home. Accessed April 16, 2013.
- Lerma EV, et al. Current Diagnosis & Treatment: Nephrology & Hypertension. New York, N.Y.: The McGraw-Hill Companies; 2009. http://www.accessmedicine.com/resourceTOC.aspx?resourceID=628. Accessed April 16, 2013.
- Peritoneal dialysis. The Merck Manuals: The Merck Manual for Healthcare Professionals. http://www.merckmanuals.com/professional/genitourinary_disorders/renal_replacement_therapy/peritoneal_dialysis.html#v1054643. Accessed April 18, 2013.
- Peritoneal dialysis: What you need to know. National Kidney Foundation. http://www.kidney.org/atoz/pdf/peritonealdialysis.pdf. Accessed April 16, 2013.
- Anderson CF (expert opinion). Mayo Clinic, Rochester, Minn. April 20, 2013.