What is peritoneal dialysis (Water Dialysis)
The peritoneum is a double set of membranes in our body that lines the abdominal cavity. There is a potential space between the membranes which is called peritoneal space, normally it contains a very small amount of fluid. In peritoneal dialysis, the peritoneum acts as a filter and waste material, extra salt and water can be removed. So, it does not involve any blood vessel access creation.
How is peritoneal dialysis done?
In peritoneal dialysis fluid (dialysate) is instilled in the peritoneal space through a plastic tube, there this liquid causes movement of undesired products from the body into the peritoneum which can then after a few hours (4-8) be drained, and fresh dialysate can again be refilled (exchange) or drained (kept dry). This process goes on slowly and almost continuously with some gaps given in between. It is a gentle form of dialysis done daily over prolonged periods. Access to the peritoneal membrane is made by a small day-care surgery in which a tube (PD catheter) is inserted through the abdomen around the umbilicus. It takes a few weeks before the PD catheter can be used for starting dialysis.
The benefits of Peritoneal dialysis over Hemodialysis
- Peritoneal dialysis being slower, daily is considered more physiologically mimicking how our kidneys work. Patients on peritoneal dialysis can have more flexible salt and water intake compared to those on hemodialysis.
- It is done in the comfort of one’s home, at the convenience of patients’ time. The patient does it themselves or a caregiver who has undergone short training. Patients do not need to go to dialysis centers where hemodialysis is generally done, hence greater independence for the patient. People who live far from dialysis centers with extreme weather conditions also get dialysis access.
- Patients on peritoneal dialysis have longer-lasting residual kidney function, which is important as the kidney performs various functions other than salt and water balance e.g., blood formation, Bone Health, and Cardiovascular health.
- Patients who have high potassium levels which are difficult to control despite adequate hemodialysis may have better control on peritoneal dialysis.
The Types of peritoneal dialysis
Continuous ambulatory peritoneal dialysis (CAPD)– In this glucose-based dialysate is filled in the peritoneal cavity and then drained. Both filling and draining are assisted by gravity and are done manually.
Automated Peritoneal dialysis (APD)– In this, an automated machine called a cycler performs the function of filling and specified time of drainage of dialysate. The machine performs multiple exchanges at night while the patient rests/sleeps.
