What is dialysis and how does it work?
Dialysis is the process of removing wastes and impurities from the blood and is done when a person’s kidney doesn’t function properly, due to kidney failure, severe diabetes, a congenital kidney disease, hypertension or other health problems.
Dialysis is a form of renal replacement therapy. Dialysis can be done for a short period, in case the patient is waiting for a kidney transplant. If the patient doesn’t qualify for the transplant, life-long dialysis will be needed.
There are two types of dialysis:
HemodialysisIn hemodialysis, a machine called a dialyser is used to filter the blood. A catheter is placed in a vein in the arm, and a needle inserted into this catheter is connected to a tube that carries blood into the dialyser. In the dialyser, a semi-permeable membrane separates the blood from a dialysis fluid. The wastes in the blood pass through the membrane into the fluid, and the clean blood is sent into the body.
In peritoneal dialysis, the abdomen is filled with a glucose-based liquid through a small hole created in the peritoneal membrane (lining of the abdominal cavity). This solution cleans the blood of wastes.
Peritoneal dialysis can be done when the patient is performing regular activities. Such dialysis is called Continuous Ambulatory Peritoneal Dialysis. The patient will be trained to infuse and drain out the fluid a few times every day. Peritoneal dialysis can also be done with the help of a machine, at night, when the patient is sleeping.
Plasma exchange may be done along with dialysis, to filter clotting factors and unwanted proteins. Charcoal hemofiltration in which a charcoal layer is used to remove wastes from blood, a process similar to dialysis, may sometimes be used.