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OHSU, Portland VA in Nationwide Dialysis Study

Results show that more is not better in treating acute kidney injury

Oregon Health & Science University and the Portland Veterans Affairs Medical Center participated in a nationwide multicenter study of critically ill patients with acute kidney injury that found a more intense than usual dialysis regimen is not beneficial and does not improve patient outcomes. A total of 37 of the 1,124 study subjects were treated at the Portland site.

The findings – published online by the New England Journal of Medicine (NEJM) – contradict several earlier single-center studies suggesting that more intensive dialysis at higher dose levels were associated with improved survival. “Given [these] results …, the renal and intensive care communities must now focus on other strategies to help this population of patients,” said Harvard Medical School professor Joseph V. Bonventre, M.D., Ph.D., in a companion editorial in the same issue of NEJM.

“This is the largest study of acute kidney injury in the intensive care setting to date and carries major implications regarding patient care, cost and utilization for renal replacement therapy in the future,” said Suzanne G. Watnick, M.D., one of the study’s co-authors and an associate professor of medicine nephrology and hypertension in the OHSU School of Medicine. She is also medical director of the Portland VA Medical Center dialysis unit.

The Veterans Affairs/National Institutes of Health Acute Renal Failures Trial Network, or ATN, study, as it is known, was conducted between November 2003 and July 2007 at 27 VA and university-affiliated medical centers. The results indicated that “a strategy of intensive renal support in critically ill patients with acute kidney injury does not decrease mortality, accelerate recovery of kidney function, or alter the rate of nonrenal organ failure as compared with a less-intensive regimen similar to usual-care practices.”

The study subjects were critically ill adults who had acute kidney injury consistent with acute tubular necrosis, or renal failure, as well as failure of one or more nonrenal organ systems or sepsis. The subjects were randomly assigned to one of two treatment groups by means of a centralized, computer-generated adaptive randomization scheme.

Of the 1,124 subjects, 561 were assigned to the intensive therapy group, which underwent an average of 5.4 sessions of intermittent hemodialysis or sustained low-efficiency dialysis per week. The remaining 561 subjects received less intensive therapy, undergoing three sessions of intermittent hemodialysis or sustained low-efficiency dialysis treatments per week. In all, 302 of the intensive therapy group, or 53.6 percent, died within 60 days after randomization compared with 289, or 51.5 percent, of those in the less intensive therapy group. A total of 85 in the intensive therapy group had complete recovery and 49 partial recovery of kidney function by day 28 compared with 102 and 50 in the less-intensive therapy group. Eighty-eight in the intensive therapy group were discharged and sent home by day 60 compared with 92 in the less intensive group.

Acute kidney injury is a common complication of acute illness, affecting 2 percent to 7 percent of hospitalized patients and more than 35 percent of critically ill patients. Artificial replacement of lost kidney function through hemodialysis or other renal replacement therapy is the mainstay treatment for these patients. But acute kidney injury is associated with in-hospital mortality rates of more than 50 percent.

The authors of the ATN study lamented that, “The optimal timing for the initiation, method, and dosing of renal replacement therapy remains uncertain more than 60 years after the first clinical use of hemodialysis in patients with acute kidney injury.”


About OHSU
Oregon Health & Science University is the state’s only health and research university, and its only academic health center. OHSU is Portland’s largest employer and the fourth largest in Oregon (excluding government), with more than 12,400 employees. The university’s size contributes to its ability to provide many services and community support activities not found anywhere else in the state. It serves patients from every corner of the state, and is a conduit for learning for more than 3,400 students and trainees. OHSU also is the source of more than 200 community outreach programs that bring health and education services to each county in the state. As a leader in research, OHSU earned $307 million in research funding in fiscal year 2007. OHSU serves as a catalyst for the region’s bioscience industry and is an incubator of discovery, averaging one new breakthrough or innovation every 2.7 days, with more than 4,100 research projects currently under way. OHSU disclosed 132 inventions in 2007 alone, and OHSU research has resulted in 33 startup companies since 2000, most of which are based in Oregon.

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