What is Dialysis?

Dialysis is a method of removing excess water, salts and waste products from the blood when the kidneys are unable to do so.  Dialysis comes in a variety of forms and it is important to work with your doctor to choose the type of dialysis that works with your lifestyle.  The two basic technologies are conventional hemodialysis where the blood leaves the body for purification and peritoneal (bloodless) dialysis that uses the body’s natural membranes to separate the wastes from the blood.

Learn more about Dialysis in our video section.

In-Center Hemodialysis

In hemodialysis, the patient’s blood is pumped from the body, through an artificial kidney and then returned to the body. The artificial kidney sends the patient’s blood through thousands of tiny tubes that are bathed in a special fluid, called dialysate. Excess water, salts, and waste products in the blood flow across the tubes into the dialysate, cleaning the blood.

Hemodialysis requires a pathway for blood to flow out of the body, into the artificial kidney, and then back in to the body. This pathway is called a “vascular access,” or simply an “access.” Hemodialysis can be done either in a dialysis center or be done at home. Dialysis is generally done three times a week for three to four hours.

Nocturnal Hemodialysis

In-center nocturnal dialysis is a technique that allows for more prolonged dialysis sessions, often lasting 6 to 8 hours.  The prolonged dialysis allows for gentler fluid removal, which is helpful for patients with weak hearts or low blood pressure.

Patients arrive at the dialysis center in the evening and start their treatment around 8 p.m. or 9 p.m. and complete their treatment between 4 a.m. and 6 a.m. Patients can receive dialysis in a chair or a bed; they typically bring their own bedding, wear pajamas, surround themselves with all the comforts of home and are able to sleep while receiving dialysis.

Home Hemodialysis

At-home dialysis is an increasingly available choice. Patients who choose home dialysis undergo training at a home dialysis center. The dialysis done at home is usually done 5 to 6 days a week.

Peritoneal Dialysis

In peritoneal “bloodless” dialysis, special fluid, dialysate, is introduced into the abdomen through a plastic catheter into the belly. The fluid remains in the body for a few hours and removes excess water, salts and waste from the blood. The fluid is then drained from the belly and discarded. Patients repeat this a few times a day every day. Peritoneal dialysis is done by the patient or family member at home and requires some training.

Dialysis Access

Patients must have a vascular access surgically placed prior to starting dialysis. Four different accesses are available:

  • AV Fistula
  • AV Graft
  • Cuffed-Tunneled Catheter
  • Peritoneal Dialysis Catheter

An AV fistula is a direct connection between the patient’s artery and one of their nearby veins.  This is the absolute BEST access a patient can have because it is all their own tissue.  The fistula resists clotting and does not become infected.

An AV graft (sometimes called a bridge graft) is an indirect connection between the artery and vein, most commonly a fabric tube is used, but donated arteries or veins can also be used.

Cuffed-Tunneled Catheter (also known as a Permacath) is place into a large vein to allow dialysis.  A catheter is a flexible, hollow tube that allows blood to flow in and out of your body.  They are most commonly used as a temporary access for up to three weeks.  It is generally placed when there is not enough time to allow a fistula to mature.