Treating Kidney Failure With Hemodialysis
II. What Dialysis Does and Doesn't Do
The most commonly used form of dialysis in the United States today is hemodialysis. Thousands of people rely on it to live, and many of these patients have been using it successfully for more than 20 years.
What Hemodialysis Can Do
Hemodialysis works by replacing some of the functions of a healthy kidney. However, it cannot do everything a normal kidney can do. After all, a kidney functions 24 hours a day, and hemodialysis treatments last for only about nine to 12 hours a week, depending on the individual patient's medical needs. The three main goals of hemodialysis are to:
- Remove wastes
Once your kidneys fail, your body has no way of eliminating the normal waste products that accumulate in your blood. Every day, your body produces creatinine (the end product of normal muscle metabolism) and BUN or blood urea nitrogen (which comes from the protein in your diet). And, if your kidneys are not working well enough to get rid of these wastes, they build to harmful levels. Hemodialysis helps control this by regularly removing harmful substances from your blood. - Eliminate excess fluid
Like healthy kidneys, hemodialysis is designed to balance the fluid in your body by removing excess salt and water—so they won't build up and cause edema (swelling), high blood pressure, heart or other problems. In fact, a major goal of each dialysis treatment is to bring you to your "dry weight," or the amount you weigh when your blood pressure is normal and your body fluids are balanced. - Keep body chemicals balanced
Hemodialysis also takes over the job of maintaining safe levels of certain important chemicals in your blood. The fluid that surrounds the artificial kidney (the dialysate, or "bath") contains substances like sodium, chloride, potassium, calcium, magnesium and bicarbonate. During dialysis, substances your body needs pass through the membrane of the artificial kidney into your blood. Things your body needs to get rid of, like wastes, pass through the membrane into the dialysate solution.
What Hemodialysis Cannot Do
As we mentioned before, hemodialysis can't do everything a normal kidney can. For instance, it can't:
- Produce hormones
Healthy kidneys play a vital role in producing and regulating certain important hormones. These include erythropoietin, or EPO, which stimulates production of red blood cells and helps prevent anemia, and renin, which regulates blood pressure. The kidneys also make an active form of vitamin D, called vitamin D3, or calcitriol, which helps to keep your bones healthy. When the kidneys fail, the body needs other sources of hormone production, but hemodialysis can't provide this. To compensate, however, many patients are given man-made forms of EPO and vitamin D3 during dialysis. You may also need to take medication to control your blood pressure and other supplements such as iron and calcium. - Cure kidney failure
Hemodialysis can help reduce many of the symptoms associated with kidney failure, but unfortunately, at the present time, there is no cure for kidney failure. People who have complete, irreversible loss of kidney function must remain on dialysis for the rest of their lives, or until they have a successful kidney transplant.However, hemodialysis needn't slow you down. For most patients, life outside of dialysis is no different. You can still work, travel (with advance planning), pursue most hobbies and interests and stay physically active. And the procedure should make you feel much better, especially if you follow your dietary guidelines carefully and take your medications exactly as prescribed.
While it's not clear just how many years dialysis can add to your life, it is certain that dialysis will extend it. And, as researchers continue to improve the dialysis process, the outlook is better and better.
