First Clinical Guidelines on Acute Kidney Injury Issued

Kate Johnson

April 29, 2011

April 29, 2011 (Las Vegas, Nevada) — Nephrologists got a sneak peak at the first-ever clinical practice guidelines on acute kidney injury, announced here at the National Kidney Foundation (NKF)'s 2011 Spring Clinical Meetings.

The guidelines were developed by Kidney Disease Improving Global Outcomes (KDIGO), an international program of the NKF, and should be published this summer. They are a push toward increasing awareness about the prevention, recognition, and management of acute kidney injury (AKI), said John Kellum, MD, co-chair of KDIGO's AKI guidelines workgroup and a nephrologist in the Department of Critical Care Medicine at the University of Pittsburgh School of Medicine in Pennsylvania.

"AKI is a prevalent problem. Upwards of two thirds of ICU [intensive care unit] patients and as many as 20% of all hospitalized patients develop acute kidney injury, so it’s a massive issue," he told Medscape Medical News. "It’s really not been well appreciated that even mild injury, resulting in small changes in renal function acutely, can have significant short-term and long-term consequences," he explained.

According to KDIGO, research in the past 10 years has identified preventable risk factors and improvements in AKI management, "which are not widely known and invariably practiced worldwide, resulting in lost opportunities to improve the care and outcomes of patients with AKI."

The guidelines, which should be published this summer, are aimed at "frontline physicians" and cover everything from defining and diagnosing AKI, the recognition and modification of risk factors, and treatment and follow-up, said Dr. Kellum.

"These guidelines recognize that frontline physicians — not just nephrologists, or intensivists — but emergency room physicians, family practitioners, general internists, radiologists, cardiologists — all the sorts of people that are likely to see these patients early on — really need to be aware of the kinds of things that lead to acute kidney injury and what kinds of things can be done about it."

While the bulk of the document "is the bread and butter that people will expect," Dr. Kellum touched on some "potentially controversial aspects" of the guidelines.

In terms of defining or diagnosing AKI, the recommendations combine 2 sets of criteria to allow for a relative or an absolute increase in creatinine. Thus, according to the RIFLE (risk, injury, failure, loss, end-stage renal disease) criteria, AKI can be diagnosed if serum creatinine increases 50% from baseline in the preceding week.

However, recognizing that patients with chronic kidney disease will already have baseline elevations, the guidelines also incorporate AKIN (Acute Kidney Injury Network) criteria, which specify an increase in creatinine of 0.3 mg/dL over 48 hours.

Patients meeting either criteria can be diagnosed as having AKI, said Dr.. Kellum.

Recommendations regarding volume replacement include an emphasis on using isotonic crystalloids as opposed to albumin or starches, a suggestion that might be "a little controversial for the international community, but I don’t think it is for the US," he said.

For volume expansion specifically as prophylaxis for contrast nephropathy, the recommendation is for isotonic sodium chloride or isotonic bicarbonate — with no preference.

"We really could have gone either way," said Dr. Kellum. "We decided at the end of the day despite data supporting bicarbonate over saline, there is no [bicarbonate] product I can reach for that is FDA [Food and Drug Administration] approved. We felt that mixing a solution in the pharmacy or at the bedside was potentially dangerous, so even though the literature supports bicarbonate-based solutions slightly over saline, we thought that the safety issue offset that. Between the two we ended up saying they were more or less equivalent."

Other potentially controversial points include the recommendation of citrate for anticoagulation in dialysis and ultrasonography-guided catheter insertion, which is "strongly recommended, with grade A evidence," he said. "This is going to be a change for many institutions but the evidence is so compelling that we felt we had to recommend the use of ultrasound."

As co-chair of the entire KDIGO group and not specifically involved in developing the AKI guideline, Kai-Uwe Eckardt, MD, professor of medicine and head of the Department of Nephrology and Hypertension at the University of Erlangen-Nuremberg in Erlangen, Germany, said he hopes the medical community will welcome the document.

"It's the first time people have sat together to go through the literature and examine the evidence for a common definition, and staging system and specific interventions," said Dr. Eckardt.

"They have been able to clarify a couple of issues and give clear guidance in simple statements from a background of 2 or 3 dozen scientific papers which an individual physician who is not an expert in the field could never review for himself, so that's useful."

Dr. Kellum disclosed grant/research support from Gambro and Cytosorbents; consultant/scientific advisor work with Gambro, Baxter, Fresinius, Ebi, Eli Lilly, Spectral, Abbott, Seimens, and Cytosorbents; and Speaker’s Bureau work with Gambro, Baxter, and Fresinius. Dr. Eckardt disclosed grant/research support from Roche; consultant/scientific advisor work with Amgen, Johnson & Johnson, Hexal/Sandoz, Affymax, and Roche; and Speaker’s Bureau work for Amgen, Johnson & Johnson, and Roche.

The National Kidney Foundation 2011 Spring Clinical Meetings: Session #227. Presented April 29, 2011.


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