Table 1.

Categorical severity stage metrics of AKI

MetricPlasma CreatinineGFR
RIFLEa
    R: riskIncrease of ≥50 and <100% above baselineDecrease of ≥25 and <50% (corrected ≥33 and <50%)b
    I: injuryIncrease of ≥100 and <200% above baselineDecrease of ≥50 and <75% (corrected ≥67 and <75%)b
    F: failureIncrease of ≥200% above baseline or ≥4 mg/dl with an acute rise of ≥0.5 mg/dlDecrease of ≥75% (corrected: ≥67%)b
    L: lossComplete loss of kidney function for >4 wk
    E: ESRDEnd-stage kidney disease for >3 mo
    AKI (total RIFLE)An acute (R or higher) and sustained (≥24 h) rise over 7 dc
AKINa
    IIncrease of ≥50% or ≥0.3 mg/dl and <100% above baselineNA
    IIIncrease of ≥100 and <200% above baselineNA
    IIIIncrease of ≥200% above baseline or ≥4 mg/dl with an acute rise of ≥0.5 mg/dlNA
    AKI (total AKIN)An acute (stage I or higher) rise over 48 h
W&B
    1Increase of ≥0.3 mg/dl over 24 h or ≥0.5 mg/dl over 48 h above baselineNA
    2Increase of ≥0.5 mg/dl over 24 h or ≥1.0 mg/dl over 48 h above baselineNA
    3Increase of ≥1.0 mg/dl over 24 h or ≥1.5 mg/dl over 48 h above baselineNA
    AKI (total W&B)An acute (stage 1 or higher) rise over 24 to 48 h
  • NA, not applicable.

  • a RIFLE and AKIN also stage AKI according to urine output (data not shown).

  • b Corrected values as in reference (10).

  • c The timing and concept of sustained did not appear in the original publication but were recommended by the ADQI group and appeared in subsequent publications (11,12).