Information
Definition- The RIFLE criteria (Risk, Injury, Failure, Loss, and ESRD [end-stage renal disease]) were developed in 2004 to standardize the definition of acute kidney injury (AKI), formerly called acute renal failure (ARF). Before this, no consensus was available on the diagnosis or degree of severity.
- Several modifications were introduced by the Acute Kidney Injury Network (AKIN) soon after, although the main addition with AKIN was a more inclusive Stage 1 (≥0.3 mg/dL increase in creatinine [Cr]).
- In 2012, the Kidney Disease Improving Global Outcomes Organization (KDIGO) published clinical practice guidelines to create a unified definition with the goal of improving outcome staging and future clinical research (because RIFLE and AKIN did not completely coincide).
- Although these (see Table 25.1) were created to help standardize clinical outcomes research, they are helpful when assessing the severity of injury and level of management (Figure 25.1).
- Serum Cr criteria: Although well validated, discrepancies exist between various definitions (eg, misclassification of AKI using AKIN in patients in postsurgical intensive care unit [ICU] after cardiopulmonary bypass with significant positive fluid balance resulting in hemodilution).
- Urine volume criteria are the same for all three (RIFLE/AKIN/KDIGO) but oftentimes they are less accurate (eg, morbid obesity).
- Validation studies are currently underway to establish the utility of these guidelines, particularly with regard to diagnosis and outcome.