When a patient suffers from renal failure, they will often undergo dialysis, also known as renal replacement therapy. Learn more about dialysis at Cleveland Clinic from our experts.
Cleveland Clinic has provided dialysis care to patients for nearly 60 years and was one of the first centers in the world to offer dialysis. Numerous scientific breakthroughs in the technology of dialysis and treatment of patients have occurred at Cleveland Clinic. We continue to offer the latest in technical advances combined with a caring, patient-center approach.
What is Dialysis?
Learn more about Cleveland Clinic's top-ranked nephrology program in the nation.
Dialysis, also known as renal replacement therapy, aims to replace the critical functions of the kidneys and sustain life in people with severe kidney failure. Another treatment option is kidney transplantation, which is outlined in a separate section.
What do the kidneys do?
Understanding the basic functions of the kidney is helpful to understanding dialysis. Each kidney contains filtering units called nephrons--about one million of them. The nephrons clean, or filter the blood of waste products that are produced every day by the body. The amounts of fluid, salts, and body chemicals circulating in the blood are regulated by the kidneys and the kidneys also produce hormones essential to blood pressure control, bone health, and red blood cell production to prevent anemia.
As the kidneys fail, a person develops a condition known as chronic kidney disease (CKD). Common blood tests that detect and measure kidney function include BUN (B-U-N or blood urea nitrogen) and creatinine. More advanced stages of CKD lead to uremia and cause lack of energy, difficulties in mental concentration, poor appetite, nausea, vomiting, anemia, difficulty breathing and ankle swelling from fluid overload, aggravated high blood pressure, and very little urine production.
Dialysis can significantly decrease the symptoms of uremia and improve overall quality of life and survival. However, dialysis replaces only a percentage of kidney function and medications, diet control, and fluid limits are also needed. Cardiovascular disease (CVD) remains the major life-threatening problem for patients on dialysis and our dialysis care involves aggressive treatment of risk factors and cardiovascular disease.
What are the two types of dialysis?
There are two types of dialysis: hemodialysis and peritoneal dialysis, both of which are available at Cleveland Clinic.
Hemodialysis uses a special filter called a dialyzer as an artificial kidney to clean your blood of waste products and remove extra fluid that has accumulated. The dialysis machine pumps blood through the dialyzer. The newly cleaned blood flows out of the dialyzer and is returned to your bloodstream. Hemodialysis uses an arterio-venous (AV) fistula or an AV Graft to access and return blood to the patient.
Most people undergo three dialysis sessions each week, for four to five hours each time using their dialysis access. During dialysis, a person also receives medications to replace hormones the kidneys are unable to produce.
Where is hemodialysis performed?
Most hemodialysis is performed at a dialysis center, under the care of doctors, nurses, and dialysis technicians with specialized training. Some patients choose to receive hemodialysis at home. Treatment at home requires additional training and an assistant care giver but allows greater independence and better control of waste products. Cleveland Clinic offers both in-center and home dialysis options.
Peritoneal dialysis utilizes the peritoneal membrane - the lining of the abdominal cavity. The peritoneal membrane is very large, and has a rich blood supply. Peritoneal dialysis is performed using a solution, called dialysate that drains into the belly spaces around the intestines and other organs. A small tube (catheter) that has been placed in a minor surgical procedure carries the dialysate in and out of the belly.
The dialysate remains for two to six hours, and the wastes, extra fluid, and excess chemicals pass from the blood vessels in the peritoneal membrane into the dialysate fluid, Then, the dialysate fluid is drained from the belly via the catheter. Once the fluid is drained, new fluid is placed to begin the process anew. Peritoneal dialysis can be performed during the day (referred to as continuous ambulatory peritoneal dialysis) or with a cycling machine overnight while you sleep (also known as continuous cycling peritoneal dialysis).
Peritoneal dialysis allows patients greater independence because they can perform the procedure on their own at home. People who are self-motivated and who have not had major abdominal surgery may be suited for this form of dialysis. The Cleveland Clinic’s peritoneal dialysis team helps patients become proficient at performing peritoneal dialysis, and is available 24 hours per day to assist patients as needed.
Some points to remember:
- Your kidneys filter wastes from your blood and regulate other functions of your body
- When your kidneys fail, you need treatment to replace the work your kidneys normally perform
- Your three choices for treatment are hemodialysis, peritoneal dialysis, and kidney transplantation
- The choice you make will affect your diet, your ability to work and other life style issues. You have the right to refuse or withdraw from treatment if you choose.
- Medicare and Medicaid pay much of the cost of treatment for kidney failure.
Why Would Someone Need Dialysis?
People whose overall kidney function is so poor that it threatens health and survival are said to have end-stage renal disease (ESRD), and need renal replacement therapy--either dialysis or kidney transplantation.When a kidney transplant is not immediately available or not possible, dialysis can replace the critical functions of the kidneys and sustain life. Today, about 350,000 people in the United States use dialysis as renal replacement therapy.
(This information comes from the National Institute of Diabetes, and Digestive, and Kidney Diseases (NIDDK). To learn more visit the NIDDK website.)
What Happens Before Dialysis?
Preparation for dialysis is dependent upon which type of dialysis that you may need. In the case of hemodialysis, a patient must first have a minor surgical procedure in the arm. The surgery creates an access for the needles needed to connect the blood circulation to the dialysis machine. This minor surgery forms either an AV (arterio-venous) fistula or an AV Graft - if artificial (Gore-Tex) material is used. In peritoneal dialysis, a small tube (catheter) must be installed in a minor surgery that will help carry dialystate in and out of the body.
What Happens After Dialysis?
Dialysis is a procedure that is prescribed for kidney failure. A patient on dialysis will continue dialysis treatment for the rest of their lives unless they receive a kidney transplant. Cleveland Clinic doctors have had immense success with kidney transplants.
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