NEW YORK (Reuters Health) - For patients with acute kidney injury, increasing the intensity of hemodialysis over recommended levels does not reduce mortality or improve renal recovery, according to a meta-analysis. [p 6 c 1 P2]
Acute kidney injury requiring renal replacement therapy (RRT) is associated with in-hospital mortality rates of up to 60%, authors say in the Clinical Journal of the American Society of Nephrology, published online on April 15. [p 1 P1]
“Single center studies showed consistent and not small effects on survival by increasing intensity,” co-investigator Dr. John A. Kellum, from the University of Pittsburgh, Pennsylvania, told Reuters Health. Also, “in chronic kidney disease there is a relationship between intensity of therapy and outcome, so our hypothesis was that there would be improvement with more intense therapy in acute injury.”
In their systematic literature review, senior author Dr. Alan Cass, from The University of Sydney, Australia, and his team identified seven randomized and one quasi-randomized trial published between 2000 and 2009 comparing lower intensity and higher intensity RRT. [p 2 c 2]
“It is theorized that more intensive therapy, through better clearance of toxins that accumulate in renal failure, will improve patient outcomes,” Dr. Cass explained in an email to Reuters Health.
Included were 3841 patients with acute kidney injury; mean age ranged between 51 and 68 years. [p 2 c 2]
Six trials assessed doses of continuous RRT, where the lower intensity dose ranged between 20 and 25 mL/kg per h and higher intensity dose ranged between 35 and 48 mL/kg per h. According to Dr. Kellum, the lower intensity dose matches professional guideline recommendations. [p 2 c 2 P 2 and Table 1]
Three trials used intermittent hemodialysis (including one trial that also used continuous RRT), where higher intensity was achieved by increasing the frequency of treatment. All trials were open-label. [p 2 c 2 P 2 & 3]
Pooled data showed that higher intensity dialysis did not reduce the risk of dying (relative risk 0.89, p = 0.143). Nor did it increase the probability of survival without the need for ongoing dialysis (RR 1.12, p = 0.181). [p 2 c 2 P 4 and p 5 c 1 and p 6]
“We were shocked,” Dr. Kellum said.
He pointed out that clinicians are in general delivering less than recommended doses of RRT to acute kidney injury patients. Based on this meta-analysis, he said, “Clinicians need to move up the level of hemodialysis intensity, but only to the recommended dose.”
“RRT is life-sustaining therapy for patients with severe AKI,” Dr. Cass said. “We need to better understand the effects of treatment modalities, doses and timing of commencement of RRT in this varied and high- risk population.”
