dialysis

Dialysis is a medical treatment that performs the functions of the kidneys for people whose kidneys no longer adequately remove waste products and excess fluids from the blood. It is used in chronic kidney disease and acute kidney injury to prevent complications of toxin buildup and fluid overload. Dialysis is a form of kidney replacement therapy and is typically lifesaving, though it does not cure the underlying kidney disease.

There are two main modalities. Hemodialysis uses a dialyzer, an artificial semipermeable membrane, to filter blood that is circulated from the body through a machine. Waste products and extra fluid diffuse across the membrane into dialysis solution and are discarded. Access is usually via an arteriovenous fistula or graft, with catheter use in some situations. Treatments are commonly performed in a clinic or at home several times per week.

Peritoneal dialysis employs the patient’s peritoneal membrane as the filter. A catheter in the abdomen fills the peritoneal cavity with dialysis solution, waste and fluid diffuse across the membrane, and the solution is drained. PD can be performed continuously at home, in patterns such as CAPD or CCPD.

Indications include progressive kidney failure with uremic symptoms, severe electrolyte disturbances, fluid overload unresponsive to medication, and certain toxin ingestions. Complications can include infections at catheter sites, peritonitis in PD, low blood pressure, electrolyte imbalances, and dialysis disequilibrium. In many cases, dialysis is paired with eventual kidney transplantation, which offers a potential cure.