Timing of renal replacement therapy initiation by AKIN classification system.

Area of Science:

• Nephrology
• Critical Care Medicine
• Clinical Research

Background:

• Previous studies on early renal replacement therapy (RRT) initiation using Acute Kidney Injury Network (AKIN)/RIFLE criteria in less severe AKI stages have not shown significant benefits.
• Defining early RRT based on less severe AKIN/RIFLE stages has historically failed to demonstrate measurable improvements in patient outcomes.

Purpose of the Study:

• To evaluate the impact of early RRT initiation on mortality and other outcomes in critically ill patients with stage 3 acute kidney injury (AKI).
• To establish a time-based definition for early versus late RRT initiation using the urine output criterion of AKIN.

Main Methods:

• Compared RRT initiation in critically ill patients, defining early RRT as initiation within 24 hours of meeting AKIN stage 3 criteria.
• Utilized urine output (UO) and serum creatinine (sCr) for AKIN criteria evaluation, excluding patients with acute-on-chronic kidney disease.
• Employed propensity score methodology to control for confounding variables and balance patient groups.

Main Results:

• Analyzed 150 critically ill patients with pure stage 3 AKI who underwent RRT.
• Mortality was significantly lower in the early RRT group (51.5%) compared to the late RRT group (77.9%, P=0.001).
• Propensity score analysis revealed a 30.5% relative decrease in mortality for early RRT initiation (P=0.002), with reduced mechanical ventilation duration, RRT time, and ICU length of stay.

Conclusions:

• This study, for the first time, utilized AKIN criteria with the urine output (UO) criterion to define and evaluate early versus late RRT.
• A time-based definition, specifically initiating RRT within 24 hours of AKI stage 3, appears to be a more effective parameter for assessing the association between RRT timing and outcomes.