Nighttime Home Dialysis a Boon for Kidney Patients
Heart health, blood pressure and quality of life improve with frequent dialysis
TUESDAY, Sept. 18, 2007 (HealthDay News) -- Undergoing dialysis at home most nights of the week may be better for some kidney patients' health than conventional three-times-a-week dialysis, new research suggests.
In a six-month randomized trial comparing frequent nocturnal dialysis to standard dialysis therapy, researchers found that heart health, blood pressure and some measures of quality of life improved for those undergoing at-home dialysis five or six nights a week.
"We strongly believe that this type of dialysis should be offered as an option to every patient who develops kidney failure," said the study's lead author, Dr. Bruce Culleton, who was an associate professor at the University of Calgary in Alberta, Canada, at the time of the study.
However, Culleton added that at-home therapy is probably a viable option for only about 10 percent to 20 percent of all kidney-failure patients, because it requires that the patients operate the dialysis machine themselves.
Results of Culleton's study are published in the Sept. 19 issue of the Journal of the American Medical Association.
Dialysis is a lifesaving procedure for people who have developed kidney failure. When the kidneys no longer function, or aren't functioning effectively enough to filter the blood well, a dialysis machine can be used to filter impurities from the blood. While dialysis isn't as effective as normally-functioning kidneys, it does remove a majority of waste and toxins from the blood. Still, dialysis patients have a high mortality rate. Each year, mortality rates exceed 15 percent, according to background information in the study.
Cardiovascular disease, including problems with the structure of the left ventricle of the heart, is often the cause of death, according to the study.
Previous research had suggested that frequent nocturnal dialysis might improve heart health and other results, but no randomized clinical trials had been done comparing the standard dialysis regimen to the at-home treatment.
Culleton and his colleagues recruited 52 dialysis patients and randomly assigned them to receive either conventional dialysis three times a week at a dialysis center or to learn at-home dialysis to be done five to six times a week for at least six hours while they were sleeping.
By the end of the six-month study period, the average left ventricular mass was 15.3 grams more for the conventional dialysis group, compared with the nocturnal dialysis group.
"These patients clearly did have improvements in heart thickness, and other studies have shown that if you reduce the size of the left ventricle, you increase survival," said Dr. Alan Kliger, chairman of medicine at the Hospital of St. Raphael and a clinical professor of medicine at Yale University School of Medicine. Kliger wrote an accompanying editorial in the same issue of the journal.
In addition to the reduction in left ventricular mass, blood pressure dropped as well for the nighttime dialysis group. Systolic blood pressure -- the top number -- went down 7 mm/Hg for the nocturnal dialysis group, compared to a 4 mm/Hg increase for the conventional group. Diastolic blood pressure also dropped 7 mm/Hg for those dialyzing at home, but decreased just 2 mm/Hg for the standard group.
Sixteen out of 26 people in the nocturnal dialysis group were able to stop taking high blood pressure medications, while only three out of 25 in the standard group stopped these medications.
There were also improvements in mineral metabolism, such as calcium and phosphate, and some improvements in quality of life, such as the burden of kidney disease, in the nightly dialysis group.
Both Culleton and Kliger said these improvements were the result of more frequent dialysis for the at-home group. "With nocturnal dialysis, the dose is much higher than with standard three-times-a-week dialysis, making it closer to what the kidneys do naturally," Kliger said.
"Patients need to know that there are other options besides standard in-center dialysis, and they need to weigh the risks and benefits and make an informed decision," Culleton said.
To learn more about the different types of dialysis, including nocturnal home dialysis, visit the National Kidney Foundation.