According to a recent article published in The Journal of the American Medical Association, different treatments for acute kidney failure lead to nearly the same mortality rate and other similar clinical outcomes. The meta-analysis was performed by Neesh Pannu of the University of Alberta, Edmonton, Canada and colleagues.

The researchers focused on treatments for acute kidney failure such as intermittent hemodialysis and continuous kidney replacement therapy (CRRT). Hemodialysis is a method for removing waste products such as potassium, urea, and free water from the blood when the kidneys are in renal failure. CRRT is a technique that allows slow dialysis over 24 hours, just like the kidney.

Acute renal (kidney) failure (ARF) is becoming more frequent, has high costs, and leads to quite negative outcomes. Patients with ARF have higher risk of death, stay in the hospital longer, and require chronic dialysis. Currently, there are several options for treating ARF that will temporarily or permanently fix the kidney’s inability to filter body fluids. These include intermittent, continuous, and extended-duration hemodialysis and hemofiltration (CRRT), and combinations of these.

Pannu and colleagues remark that, “Despite advances in dialysis technology, many questions remain about how best to provide renal replacement to patients with ARF.”

The researchers reviewed and evaluated current evidence optimal management of dialysis for patients with ARF. The article search focused on studies that examined dialytic support in adults with ARF and that reported the incidence of outcomes such as death, length of hospital stay, need for repeated dialysis, or development abnormally low blood pressure (hypotension). Thirty randomized controlled trials (RCTs) and 8 prospective cohort studies were included in the study from 173 retrieved articles.

After analyzing the 38 studies, the researchers determined that no conclusions could be drawn about the best indications for or timing of renal replacement. It was demonstrated that the treatments CRRT and intermittent hemodialysis did not have any clinically relevant difference in risk of death or for the need for frequent dialysis treatment in survivors. The studies also lacked any evidence that CRRT or intermittent hemodialysis was more cost efficient or better at reducing the risk of chronic dialysis dependence in ARF patients.

The researchers comment on the suggested treatment strategy for patients with severe ARF: “The decision to initiate renal replacement therapy (RRT) in patients with severe ARF requires consideration of multiple factors, including assessment of intravascular volume, electrolyte and acid-base status, uremia [retention in the bloodstream of waste products normally excreted in the urine], nutritional requirements, urine output, hemodynamic status, and the evolving clinical course of each patient. Potential advantages of earlier RRT initiation must be set against the hypothetical risks of treatment-induced renal injury, bleeding due to anticoagulation, and mechanical and infectious complications associated with central venous access.”

“Given the significantly higher cost of CRRT, intermittent hemodialysis may be preferable for patients with ARF who require RRT. In otherwise stable patients, alternate-day dialysis treatments of 4 or more hours using blood flows of 250 mL/min or greater are usually sufficient in patients with or without concomitant critical illness. More frequent hemodialysis may be required in highly catabolic [a destructive metabolic process] patients or to achieve treatment targets for fluid, electrolyte, or acid-base management, although data identifying how such targets should be set are limited. Despite the lack of data supporting its superiority and its higher cost, some clinicians may prefer to use CRRT in critically ill patients with ARF and severe hemodynamic instability. If CRRT is used, the target dose should be 35 mL/kg per hour [3 L/h in a 154 lb. person],” conclude the authors.

Renal Replacement Therapy in Patients With Acute Renal Failure
Neesh Pannu, Scott Klarenbach, Natasha Wiebe, Braden Manns, and Marcello Tonelli
JAMA. (2008). Vol. 299 No. 7: pp. 793-805
Click Here to View Abstract

Written by: Peter M Crosta