Kidney Replacement Therapy
Diabetes sometimes damages kidneys so badly that they no longer work. When kidneys fail, the person needs to replace their function with either dialysis or a transplant.
Dialysis, the more common form of kidney-replacement therapy, is a way of cleaning the blood with an artificial kidney. There are two types of dialysis: hemodialysis and peritoneal dialysis.
No matter which type is chosen, the person undergoing dialysis needs to work closely with the health care team to keep diabetes under control.
In hemodialysis, an artificial kidney removes waste from the blood. A surgeon must first create an "access," a place where blood can easily be taken from the body and sent to the artificial kidney for cleaning. The access, usually in the forearm, can be made from the patient's own blood vessels or from a piece of implanted tubing. The access is inside the body and cannot be seen from the outside. Usually, this surgery is done 2 to 3 months before dialysis starts so the body has time to heal.
Hemodialysis must be done 2 to 3 days per week, and lasts 3 to 5 hours each time. Blood travels through the artificial kidney, where waste products are filtered out, and the clean blood returns to the body. Only about 1/2 cup of blood is out of your body at any one time.
Usually, hemodialysis is done in a clinic, with many people receiving dialysis at the same time. Hemodialysis can also be done at home, but it requires a partner, such as a relative or friend, and special training.
Hemodialysis is not perfect for everyone. During treatments, people can have high or low blood pressure, an upset stomach or muscle cramps. A special diet is needed to stay healthy. Other problems can develop over time, such as nerve problems, anemia, bone disease, poor nutrition, problems with infection, problems with the access, and difficulty regulating insulin doses. Sometimes, these complications are the result of diabetes, not of hemodialysis.
Another form of dialysis is called peritoneal dialysis. The lining inside your abdomen (the peritoneum) becomes the filter. A soft plastic tube is put into the abdomen by a surgeon. When the body heals, cleansing fluid (dialysate) is put into the abdomen through this tube. Waste products in the bloodstream pass through the peritoneum into the dialysate. Then the dialysate, along with the waste products is drained off.
The two main types of peritoneal dialysis are continuous ambulatory peritoneal dialysis (CAPD) and continuous cycling peritoneal dialysis (CCPD). People perform CAPD themselves by attaching a plastic bag filled with cleansing fluid to the tube in the abdomen and raising it to shoulder level. This causes the fluid to run into the abdomen. The bag is then unhooked or rolled up around the waist. In several hours, the fluid is drained out and thrown away. A fresh bag of fluid is then put into the abdomen to begin cleansing again. This is called an "exchange" and takes about 30-45 minutes. It is done 4 or 5 times a day. Between exchanges, the person can move around and perform daily activities.
In CCPD, a machine puts the cleansing fluid into the abdomen and drains it automatically. This is usually done at night during sleep.
CAPD and CCPD may be better treatments than hemodialysis for some people. With daily dialysis, the body does not build up too much fluid. This reduces the stress on the heart and blood vessels. A person is able to eat a more normal diet and have more time for work and travel.
Peritoneal dialysis is not for everyone, however. A person must be able to see well and do each step correctly to prevent infection in the abdomen. Anemia, bone disease, and poor nutrition can occur, just like in hemodialysis.
Your doctor will help you decide whether hemodialysis or peritoneal dialysis is right for you. Diabetes control remains important no matter which type of dialysis is chosen.
Please note, the U.S. Food and Drug Administration (FDA) has reported that diabetes patients undergoing peritoneal dialysis with EXTRANEAL (icodextrin) may have inaccurately high blood glucose level results with some home blood glucose meters. This could potentially lead to low blood glucose (hypoglycemia) if these inaccurate readings are used to make decisions about insulin or medication doses. If you are a patient undergoing peritoneal dialysis, you should find out if your blood glucose meter utilizes the testing method (GDH-PQQ enzyme) that may cause the problem. To find out, please call the company that makes your blood glucose meter (a toll-free phone number is generally on the back on the meter) to inquire about your meter and possible alternatives.
One option for the person with ESRD is a new kidney. Transplants are most successful when the kidney comes from a living relative. Another option is a cadaver kidney (a kidney from an unrelated person who has just died).
What is the success rate?
One year after getting a kidney from a living relative, about 97% of people with diabetes are still alive. After 5 years, the number is approximately 83%. For people who get cadaver kidneys, about 93% are still alive after 1 year, and 75% are alive after 5 years.
These numbers may sound scary, but people who have kidney failure will die without treatment. For those who choose dialysis, only about 33% are still alive 5 years later. So although kidney transplantation is a serious operation, it offers people with ESRD their best chance for survival.
The body has a complex system for telling its own parts from foreign parts. To fool the body into accepting the donor organ, doctors try to match the donor and recipient for a blood protein called human leukocyte antigen (HLA) type. A good match is most important when using a kidney from a living donor. The evidence for the value of HLA matching with cadaver kidneys is less clear. Some doctors believe that, at least in African Americans, cadaver kidneys all "take" equally well.
How hard is it to get a kidney?
Unfortunately, there are too few kidneys for all the people who need them. Not enough people sign up to be organ donors. The shortage persists even though each person gets only one kidney at a time. Although the body normally has two kidneys, it can get by with just one as long as that kidney is healthy and working well.
Federal law says that kidneys should be given out in a fair and efficient way. In the current system, a national list contains the names and HLA types of people who need cadaver kidneys. When a kidney donor's kidneys become available, doctors check the list to see whose HLA types best match that of the donor. If there are several people who match equally well, the two people waiting longest get the kidneys. Some people must wait years before a kidney becomes available. Those waiting use dialysis in the meantime.
What about rejection?
Despite the best HLA matching, the body may still not recognize the new kidney as part of itself. For this reason, people with kidney transplants must take certain drugs the rest of their lives. These drugs are called immunosuppressants, because they suppress the immune system to keep it from fighting the new organ. These drugs include azathioprine and cyclosporine A. Despite these drugs, some kidney transplants fail. When the body attacks the new organ as foreign, it is called rejection.
Immunosuppressant drugs pose dangers. Although suppressing the immune system keeps it from noticing the foreign organ, it also keeps the immune system from noticing infections. As a result, the person can get sick more easily. These drugs also have many side effects.
A new kidney does not cure diabetes, and the disease may damage the new kidney just as it did the original ones. But it took many years for the person's own kidneys to fail. If the new kidney does develop diabetic nephropathy, it too will take many years to fail.
What are the risks?
Kidney transplants are safest in people who do not have heart or blood vessel disease. Before you get a transplant, your doctor will check your circulatory system to see if it is healthy enough to risk the operation.
As with any operation, the healthier you are, the better you can withstand the physical stress of surgery. Possible side effects of surgery include bleeding and infection.
Immunosuppressive drugs are hard on the body, but people who get transplants must take these drugs the rest of their lives. Azathioprine and cyclosporine, two commonly used drugs, make it easier for you to get infections and have other side effects. You will need to avoid people who have infections, such as a cold or the flu. Also, you should not be immunized without first checking with your doctor. These drugs can also damage the kidneys. For example, using either of these medicines for many years could increase your risk for some cancers.
Because of these risks, kidney transplants are done only in people whose kidneys are failing.