New hemodialysis system lets patients treat themselves at home

July 26, 2004

A new hemodialysis system that enables people with end-stage renal disease to treat themselves daily at home has already made a difference for Dadi Ding, a former dialysis nurse and a long-term dialysis patient, who recently became the first person in the Chicago area to use the new home-based system.

"I feel so much better," said Ding. "I hate to skip a day. I dialyze seven times a week."

Thanks to the home system she feels good enough to work long and unpredictable hours at her stressful job as a nurse for kidney transplant patients. She has gained enough free time to go out with friends and do volunteer work on weekends. She has even taken herself off of the waiting list for a kidney transplant. "I still want that, eventually" she says, "but not just yet."

Dialysis serves as a replacement kidney, removing waste products and excess fluid from the body. Several studies have found that short daily dialysis is safe and more beneficial than the standard practice of dialyzing for four hours three times a week. Patients who dialyze daily report feeling better, having more energy and better appetites. They have improved blood pressures, report less fatigue, insomnia and thirst, and have fewer dialysis related symptoms such as cramps or headaches.

"Healthy kidneys work around the clock," explained Orly Kohn, MD, assistant professor of medicine and director of the Home Dialysis Unit at the University of Chicago Hospitals, "but traditional hemodialysis means you get the benefits of a mechanical kidney for only a few hours three times a week. It's not physiological. It's not how nature designed the body to work."

"Daily dialysis is far from perfect," she added, "but it's much more like normal kidney function. At last it's becoming a practical option for patients."

Being dialyzed every two to three days instead of daily results in wide fluctuations of fluid levels, blood pressure and blood chemistry. As a result, dialysis patients often have decreased quality of life as well as multiple health problems, including a substantially increased risk of death. The mortality rate for dialysis patients exceeds 20 percent per year.

But until quite recently daily dialysis has been very difficult to arrange. More than 275,000 people in the United States rely on dialysis -- a number expect to double in ten years -- and nearly 250,000 of those patients are treated at hemodialysis centers, which have limited capacity. Dialysis centers care for multiple shifts of patients who come in on alternate days, and most are far too busy to be able to provide dialysis to the patients every day.

Daily home dialysis appears to reduce these problems but there has not been a convenient, reliable system. Previous devices have not caught on because they were complicated and difficult to use. Plus they were expensive, bulky and time-consuming.

Since February, however, Ding has been dialyzing every day at home using a compact, low maintenance, highly automated system produced by Aksys Ltd., of Lincolnshire, Illinois. It allows her to dialyze whenever she chooses, usually in the evening after work. She can connect quickly, within less than 30 minutes, spend 100 to 120 minutes chatting with her husband, reading or watching television while on the machine, then disconnect and clean up within 15 minutes.

"It saves me almost 90 minutes a day," she says, "not counting the extra time it would take to travel back and forth to a dialysis center, where I would have to follow their schedule, not mine."

The system is much smaller than traditional machines, fitting easily in her family room. An entire year of home dialysis supplies fits in a closet, requiring only 20 cubic feet of storage space, compared to the 260 cubic feet required for traditional hemodialysis supplies.

Ding, 49, has been forced to become quite an expert on dialysis. She has suffered from kidney problems since she was two years old. Born in China, she came to the United States when she was 18 for a kidney transplant from her brother, but once she arrived her doctors found that they were not immunologically compatible.

She did get a transplant from a cadaver donor in 1982 but it quickly failed, leaving her dependent on dialysis, which was not then available in China. For ten years she was able to perform peritoneal dialysis, a system that uses an abdominal membrane to filter waste products and excess fluids out of the blood - a process that can be done at home. Ironically, at the time Ding began her career working with dialysis patients as a nurse.

After another failed transplant attempt, however, an infection and accumulated scar tissue damaged her peritoneal membrane in 1991, and she could no longer rely on a peritoneal system.

Unwilling to let her disease force her to quit working or take over her life, Ding was able to find a clinic that would set her up with a traditional home dialysis system. But over time the inconvenience, time demands and sub-optimal results drove her to search for something more "user-friendly." She heard about the Aksys system and began searching for a program, which led her to Dr. Kohn.

"We were quite interested in starting a home hemodialysis program and she was the perfect first patient," said Kohn. "She was impressively well informed, knew all the alternatives and has the resolve and vision of a pioneer."

"We can clearly see that she is feeling better using this system," added Kohn. "She does not have the wide fluid level or blood solute fluctuations we see in patients treated less often. She has no cramps or nausea on the machine. She can eat the fruits and vegetable she loves, thanks to improved potassium control. And she's enjoying the free time she gets from reducing the set-up and clean-up times."

Kohn hopes to increase the number of patients in the home hemodialysis program to about 20% of the total hemodialysis patients at the University of Chicago.

"It's not for everyone," she said. "This is for motivated patients, involved in their own treatment, willing to learn, with good family support. It requires a few weeks of training and a long term commitment."

Initial costs are higher than traditional dialysis. The system does require special home plumbing, which costs about $1,500 and has not been covered by insurance. In the long run the overall costs are equivalent or lower due to savings on labor and fewer hospital admissions. Kohn is trying to contract a plumber familiar with the requirements and willing to discount the service.

"The next thing" says Ding, "is for them to adapt this machine to work while I sleep."