Peritoneal Dialysis

Peritoneal Dialysis is a form of dialysis where a special fluid is infused into the peritoneal cavity - a container in the stomach which is surrounded by arteries and veins through which blood flows. The excess wastes from these blood vessels diffuses into the fluid through a semi-permeable membrane that encloses the peritoneal cavity.

Peritoneal dialysis can be done in two main ways:

1. Continuous Ambulatory (CAPD): Here the fluid is infused into the peritoneal cavity and left there for about 3 to 6 hours during which time the dialyzor can go about his routine activities such as office work, exercise, watch a movie, travel etc. After this period, the fluid is removed because it has removed a lot of waste from the blood and cannot remove too much more.

Fresh fluid is infused and the process repeats. The removal of old fluid and infusion of fresh fluid is called an 'exchange'. Most people require about 3 to 4 exchanges. The fluid volume that is infused can vary between 1 to 3 liters depending on the person's weight and size.

2. Continuous Cyclic (CCPD): Here the exchanges are usually performed by a machine called a Cycler. The dialyzor connects to a machine before sleeping at night. The machine then infuses fresh fluid and removes it after 2-3 hours and infuses fresh fluid. Usually the cycles are shorter than in CAPD.

Some people adopt a mix of both CAPD and CCPD. They hook up to the machine and do a few cycles at night, infuse fresh fluid in the morning before getting off the machine and then do one mid-day exchange. This offers better removal of wastes.

For peritoneal dialysis to be performed, a tube is inserted into the stomach to enable fluid removal and filling. It will look something like this: