In peritoneal dialysis, the dialysis solution is introduced into the peritoneal cavity and left for a prescribed dwell time. During this time, waste products and excess fluids pass from the blood vessels in the peritoneum into the dialysis solution. After the dwell time, the solution, now containing waste and excess fluids, is drained out and replaced with fresh solution. This exchange process is repeated several times a day in CAPD or automatically during the night in APD.
