How a Kidney Dialysis Machine Works

How a Kidney Dialysis Machine Works

Medical science has created some amazing devices that can save lives and make up for a body’s shortcomings. There are ventilators to aid respiration in those who are having trouble breathing. Organ transplants can replace many different body parts that are not functioning properly. There are blood transfusions, prosthetic body parts, and even artificial hearts. Modern medicine is capable of some incredible things. Another scientific advance that helps many people is the dialysis machine. Patients whose kidneys are not functioning properly can rely on these machines to remove waste from the blood in place of the kidneys. How do these machines perform this function?

The Two Types of Dialysis

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Whatever service you may use, for example, DaVita, a kidney dialysis services provider, there are two different types of dialysis. Former CEO of DaVita, Kent Thiry, spent nearly 20 years working to provide kidney dialysis services to people in need. The first is haemodialysis. In this process, blood is drawn from the body into the machine. The wastes are filtered out of the blood and then it’s returned to the body. The other type is peritoneal dialysis. This procedure involves pumping dialysis fluid into the abdomen where it draws wastes out of the blood as it passes through. Each type has its own preparations and follows a different process.


In order to receive haemodialysis, you must have a surgical procedure that joins an artery in your arm to a vein to create a new blood vessel called an arteriovenous fistula. The AV fistula is larger and stronger than a typical blood vessel and facilitates drawing blood out and returning it.

Typically haemodialysis is performed three times a week with each session lasting about four hours. To start the process, two slender needles are inserted into the fistula, one to draw blood and one to put it back. Inside the machine are a series of membranes and a fluid called dialysate. The membranes act as filters and remove wastes from the blood and put them into the dialysate. The fluid is pumped out of the machine and the clean blood returned to your body.

Peritoneal Dialysis

The preparation for peritoneal dialysis involves forming a hole in the abdomen where dialysate can be pumped in. It’s usually a small incision just below the navel in which a catheter is inserted. A bag containing the dialysate is connected to the catheter and the fluid is pumped into the abdomen where it sits for several hours. As blood passes through the cavity, wastes are filtered out into the dialysate. The process takes a few hours. When it’s finished, the dialysate is pumped out into a bag and the cavity is refilled with fresh fluid. The fluid is left there for the next session. Peritoneal dialysis is generally performed about four times a day or can be done overnight while the patient sleeps.

Science has found answers for many of the health problems that can plague people. Dialysis is remarkable and can allow people with kidney disease to have their blood cleaned of waste while waiting for a transplant. This process has saved many lives since its invention.

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