Daily Dialysis Backed for Acute Kidney Failure
Study finds it cuts death rate and improves renal function faster
WEDNESDAY, Jan. 30, 2002 (HealthDayNews) -- Daily dialysis can resolve acute kidney failure almost twice as fast as conventional renal therapy and significantly reduce a patient's risk of death, a new German study says.
The findings show that intensive care patients who have the blood-cleaning procedure every day, as opposed to every two days, suffer fewer kidney-related complications and are less likely to die of other causes.
Experts say quicker improvement in renal function associated with more intensive dialysis, which scrubs the blood when kidneys can't, eases the strain on other organs from toxins that would otherwise damage them.
"To have recovery earlier is a big advantage, and that translates here into better survival altogether," says Dr. Friedrich K. Port, a dialysis expert at the University of Michigan in Ann Arbor.
A report on the findings appears in tomorrow's issue of the New England Journal of Medicine.
Many clinics in the United States perform daily dialysis for patients with acute renal failure, and many others offer a continuous procedure that Port says may be gentler on the body. However, alternate-day dialysis is generally considered cheaper than either of those methods, which may to a large degree encourage its use, he says.
Acute kidney failure often results from severe burns, exposure to toxins, and car wrecks and other traumas that lead to massive blood loss. It differs from chronic kidney failure, which is typically caused by gradually scarring of the waste-processing organs by diabetes or high blood pressure.
An estimated 240,000 Americans have end-stage kidney disease, which kills more than 67,000 people a year in this country, according to the National Kidney Foundation. Costs of treating the condition, including dialysis, run nearly $18 billion a year.
Experts believe the intensity of dialysis for chronic kidney patients is inversely related to their risk of complications and death. But no such agreement exists for acute renal patients.
In the new study, a team led by Dr. Helmut Schiffl, a kidney specialist at the University of Munich, compared daily dialysis with intermittent blood cleaning in 160 men and women with acute renal failure. Fourteen people dropped from the main study, leaving 74 in the daily dialysis group and 72 treated every other day.
Overall, 59, or 37 percent, of the original 160 patients died during the trial period. However, only 19, or 26 percent, of those in the daily dialysis arm died, compared with 31, or 43 percent, of those in the other group. After adjusting for other risk factors, less frequent dialysis appeared to be an independent predictor of death, the researchers add.
Patients who underwent intensive blood cleaning had markedly fewer toxins in their urine than those in the other group. They had fewer bouts of low blood pressure during dialysis -- 5 percent versus 25 percent -- and those with normal urine output were more likely to stay that way than were patients on the conventional regimen.
Daily dialysis patients also suffered fewer bouts of inflammation, blood infection, gastric bleeding and respiratory failure than the other group.
Dr. Robert Lindsay, a kidney expert at the University of Western Ontario in London, says the German trial included a somewhat healthier population than the average intensive care patients with acute renal failure, since only 37 percent died during the study. That's roughly half as many as would normally be expected, he notes.
On the other hand, in many studies patients with acute kidney failure die of their underlying condition, so it's difficult to sift out the benefits of a particular dialysis method. Therefore, the latest work may be a clearer reflection of the advantage of intensive dialysis over conventional therapy.
Dr. Joseph V. Bonventre, a Harvard University nephrologist and author of an editorial accompanying the journal article, agrees the patient population in the study was atypical. He also points out the German researchers used less aggressive dialysis for the conventional arm than they did in the daily group.
"It may very well be that in a group where you were more aggressive, you may then have a result that's comparable" for the two methods, he says.
Bonventre says the study forces kidney specialists to consider daily dialysis as an alternative in patients with acute renal failure. "But I don't think that it should be taken as absolutely proven" that it's better than the conventional approach. Nor, he adds, should doctors assume either technique is better than continuous dialysis until researchers conduct a three-way study.
What To Do
The National Institute of Diabetes & Digestive & Kidney Diseases has more on kidney conditions and dialysis.
And for an inside look at dialysis, check out HowStuffWorks.