Early initiation of renal replacement therapy (RRT) significantly improves 90-day survival among critically ill patients with acute kidney injury (AKI), researchers reported at the European Renal Association-European Dialysis and Transplant Association 53rd Congress in Vienna.
In a randomized single-center trial that enrolled 231 patients, Alexander Zarbock, MD, of the University of Muenster in Germany, and colleagues found that early initiation of RRT was associated with a significant 34% decreased risk of death compared with delayed initiation.
The investigators defined early RRT as RRT started within 8 hours of a diagnosis of Kidney Disease: Improving Global Outcomes (KDIGO) stage 2 AKI and delayed RRT as RRT started within 12 hours of KDIGO stage 3 AKI or no RRT initiation.
Of the 231 patients, 112 and 119 were randomly assigned to the early and delayed RRT groups, respectively. RRT for all patients was continuous venovenous hemodiafiltration. At 90 days, 68 patients in the early group (60.7%) were alive compared with 54 (45.3%) in the late group.
In addition, 60 patients in the early group (53.6%) had recovered renal function at day 90 versus 46 (38.7%) in the late group. Early RRT was associated with a significant 83% increased likelihood of recovering renal function compared with delayed RRT.
Duration of RRT and length of hospital stay were significantly shorter in the early group than the delayed group (median 9 vs 25 days and median 51 vs 82 days, respectively), but investigators observed no significant effect on requirement for RRT after day 90.
Presentation of the study’s findings coincided with the May 22 online publication of the findings in the Journal of American Medical Association, where the authors concluded: “Our study provides important feasibility data for an AKI stage-based, biomarker-guided intervention trial in AKI. However, an adequately powered multicenter trial is needed to confirm our results and establish the best time point for the initiation of RRT in critically ill patients with AKI.”
With regard to study limitations, the authors noted that although they detected a large mortality difference, “this was not a multicenter trial, and as with many single-center studies, the observed effect size is likely inflated.”
Larger trials are needed because small trials cannot avoid small baseline differences, according to the investigators. In addition, the study has limited generalizability because almost all enrolled subjects were surgical patients.
In an accompanying JAMA editorial, Glenn M. Chertow, MD, MPH, of Stanford University School of Medicine in Palo Alto, CA, and Wolfgang C. Winkelmayer, MD, MPH, ScD, of Baylor College of Medicine in Houston, wrote: “Whether the findings reported by Zarbock et al represent a plausible effect or not, the investigators have performed a rigorous trial and have presented their results appropriately, with responsible and conservative reporting.”