Dialysis more often doesn't help patients


BY ANGELA STEWART
01 jun 2008--Giving critically ill kidney patients dialysis more than the standard three times a week does not improve their survival, a study has found.
The research was based on outcomes of 1,124 patients who were randomly assigned to receive either conventional thrice-weekly treatment or a more intensive regimen involving an average of 5.4 treatments per week. The death rate for patients who received the more intense treatment was about the same as that of patients receiving the standard dose, the study found.
"There will need to be new directions pursued because merely ramping up the dose of dialysis is not going to be the answer to improving outcomes," said study co-author Paul Palevsky, chief of the renal section for the VA Pittsburgh Healthcare System.
The study, funded by the U.S. Department of Veterans Affairs and the National Institute of Diabetes and Digestive and Kidney Diseases, is scheduled to be published in the July 3 New England Journal of Medicine. It was released yesterday to coincide with the International Conference of the American Thoracic Society.
Unlike chronic kidney disease, a long-term illness associated with high blood pressure and diabetes, acute kidney failure comes on suddenly. It affects more than 35 percent of critically ill hospitalized patients and is often linked with severe sepsis, a systemic bodily infection that can lead to organ failure.
Mortality rates for hospitalized patients suffering from chronic kidney disease can range from 50 to 80 percent. Some smaller studies conducted at single institutions have suggested that more intense dialysis produces better outcomes in these very sick patients. The latest study, involving a far larger number of patients and conducted at 27 centers around the country, contradicted those findings.
"This study now confirms that as long as the dialysis treatments are well designed and effective, three times a week is adequate," agreed Joseph Bonventre, a physician at Brigham and Women's Hospital Boston who wrote an editorial accompanying the study.
In the study, Palevsky's team randomly assigned 1,124 patients with acute kidney disease to receive intensive or less intensive dialysis. The researchers found that the rate of death was 53.6 percent among patients receiving intensive renal therapy and 51.5 percent among patients receiving less intensive therapy.
Palevsky and his team concluded that the findings represented "no significant difference in mortality." Nor was any significant difference seen between the two groups in recovery of kidney function or the rate of other organs failing.
"It doesn't mean that the dose of dialysis isn't important, but once you achieve what would be the standard dose, going beyond that, there is no science to support it," said James McAnally, chief of nephrology at Trinitas Hospital in Elizabeth, who was not involved with the study.
Others, however, cautioned that the results should not be overinterpreted, citing instances such as with congestive heart failure patients when standard treatment may be inadequate.
"Many of our patients are so ill, they may require a fourth treatment just to remove fluid or control the level of poisons," said Neil Lyman, chief of nephrology and director of dialysis at Saint Barnabas Medical Center in Livingston.
"You have to make allowances for each clinical circumstance of the patient being managed," added Stanley Harris, medical director for Horizon Blue Cross Blue Shield of New Jersey, which leaves the decision up to doctors.