Nephrology

New study confirms value of home dialysis

CALGARY – A just-completed study on nocturnal dialysis is the most comprehensive ever done in the world on the night-time treatment and offers kidney disease sufferers hope of improved cardiovascular health and greater quality of life.

“It thins out the heart, and that’s a good thing,” says Dr. Braden Manns, a nephrologist at the Foothills Medical Centre who oversaw the study, along with Dr. Bruce Culleton. “People with thick hearts have a higher chance of dying, and treatments that reduce the thickness of the heart in the general population are associated with improved survival’.

“For these dialysis patients, we know that this treatment thins out the heart, although in this group of patients, we don’t yet know if this improves survival, but there is a hope. We don’t exactly know what that means. We think it’s good. The bigger deal is people seem to feel better on nocturnal dialysis, despite the fact they had to do dialysis every night, they had to hook themselves up and they had to clean the machine in the morning.”

What’s more, added Dr. Manns, “On average, patients treated with nocturnal dialysis actually felt that kidney disease was less of a burden on their life. There was less interruption on their lifestyle.”

Calgary, Edmonton, B.C., London, Ont. and Toronto are the only centres in Canada currently offering nocturnal dialysis.

Calgary is the only place that has studied the treatment in a randomized fashion.

“In nephrology we have a paucity of high quality clinical studies,” says Manns. “Perhaps that’s because historically without dialysis, patients with kidney failure died, and now with dialysis they live. That type of evidence was all that was required at the time, and that experience has possibly affected the level of evidence that we are willing to accept. For instance, if we’re offered a new dialysis filter, we often just look at the specifications sheet and say ‘oh that’s better, we’ll just use it, rather than studying it in a proper fashion’”

“We jump on the bandwagon based on poor quality studies,” he adds. “This is the first study that’s actually been randomized in terms of nocturnal dialysis. The previous studies were very small, only 20 people, this is 51. It’s still a very small study. But for a variety of reasons this may be as big a study as we’re ever going to get.”

The two-and-a-half year study was administered at the Foothills Medical Centre with the support of the University of Calgary, Alberta Kidney Disease Network and Libin Cardiovascular Institute of Alberta. Half of the patients in the study, 26, were randomly treated with nocturnal dialysis while the other 25 were continued on conventional, three-times-per-week hemodialysis. Each patient was studied for six months and those on hemodialysis were given the option of switching to nocturnal dialysis at the end of the study.

“We had a very good control group,” says Manns. “We were able to see what happens without nocturnal dialysis and what happens with nocturnal dialysis. That’s what we were able to do that no one else has been able to do. What we showed is that things that had been found in previous studies were in fact true, but others were not.

With nocturnal dialysis, patients hook themselves up to the machine that cleans their blood in place of their failed kidneys six nights a week. It takes about half an hour to set up the machine each night and another half hour to an hour to clean it in the morning.

In regular hemodialysis, patients must travel to a hospital or other care centre three times a week for four-hour dialysis sessions. Factor in travel and waiting time, and that is a six or seven hour commitment, three days a week.

Peritoneal dialysis is a system that allows patients to perform their own dialysis. About 1,500 people in Southern Alberta are on dialysis and another 1,500 have had kidney transplants.

Dr. Manns says people on dialysis, on average, have a 17 percent chance of dying every year.

All kinds of dialysis have drawbacks. Hemodialysis is a big time commitment and, because patients only get 12 hours of treatment a week, it affects their energy level.

“In addition to the fact that there’s a high chance of you dying, the quality of life isn’t very good,” says Dr. Manns of hemodialysis. “It’s similar to what advanced cancer patients are describing. They don’t have great energy, their diet is very restrictive, they can’t drink very much fluid, and so for lots of reasons, the quality of life isn’t very good.”

With peritoneal dialysis, patients must live with a tube protruding from their abdomens.

Nocturnal dialysis is a very intensive treatment that requires four to six weeks of full-time training for each patient. It is very expensive, requiring patients having their own dialysis machines and a daily supply of products for the machine.

On the plus side, the dialysis is done while the patient is sleeping, freeing up the daytime hours for work, school or relaxation.

“For some people, nocturnal hemodialysis would not be a good choice,” says Dr. Manns. “They would be uncomfortable doing dialysis by themselves at home. When we were enrolling patients in our study, only about 10 percent of our patients were interested in doing nocturnal dialysis, though more would be capable of learning to do the treatment themselves.” But for those 10 percent, nocturnal dialysis is another option for their treatment.

“We want to be able to offer enough treatment options so people are able to choose a treatment that fits into their lifestyle,” says Dr. Manns. “Nocturnal dialysis is a great treatment for people who work during the day.

“Most people on dialysis aren’t working, given that dialysis is such a big commitment, seven hours a day three times a week. By and large, the people on nocturnal dialysis are a little bit younger. By younger I mean less than 65 and often they have fewer other medical conditions going on as well.

“If people are willing to trade off more extensive dialysis, six nights a week, they will likely experience a better quality of life and they will have lower risk of cardiovascular disease.”

While the study is the biggest ever undertaken, 51 patients, and was randomized, Dr. Manns says a bigger study would have been better. “The main thing we were looking at was the thickness of the patient’s heart,” says Dr. Manns. “We saw that the thickness was reduced by about 10 percent on nighttime dialysis.

“We know that in the general population, patients who receive treatments that reduce the thickness of the heart muscle typically live longer. But we’ve only studied 51 patients for six months. To actually show a difference in survival, we would have had to study about 3,000 patients for at least a year. That study is probably never going to be done.”