Peritoneal dialysis utilizes an indwelling catheter to perform exchanges of dialysate with a specified solute concentration and osmolality into the peritoneum, which serves as a semipermeable membrane and allows for diffusion of solutes and osmosis of water. Dialysate needs to be exchanged about three to five times per day to maintain a high concentration gradient and maintain adequate solute clearance. Patients can perform these exchanges during the day, or a cycler can be used to exchange the fluid overnight while the patient sleeps; these options provide greater autonomy because the patient can work or perform activities during the day, rather than the need to be present at a hemodialysis unit three times per week. Clinical outcomes are similar for patients on peritoneal dialysis compared with hemodialysis, although patients starting RRT who have residual renal function may have better outcomes with peritoneal dialysis. Furthermore, residual renal function is preserved longer in peritoneal dialysis compared with hemodialysis and, although small, helps maintain adequate solute clearance and euvolemia.
Peritonitis is an important complication because repeated infections can cause peritoneal fibrosis and reduce the efficacy of the dialysis treatments. Dialysis–associated peritoneal peritonitis is infrequent, with an average of one episode every 2 to 3 years. It is usually caused by gram-positive skin flora and less commonly by gram-negative intestinal flora. Proper skin hygiene and sterile technique when handling the peritoneal dialysis catheter are critical in preventing peritonitis.