Table 1.

RIFLE classificationa

CategoryGFR CriteriaUO Criteria
Risk (R)Increased creatinine ×1.5 or GFR ↓ by 25%UO <0.5 ml/kg per h × 6 h
Injury (I)Increased creatinine ×2 or GFR ↓ by 50%UO <0.5 ml/kg per h × 12 h
Failure (F)Increased creatinine ×3 or GFR ↓ by 75% or creatinine ≥350 μmol/L (rise at least 44 μmol/L)UO <0.3 ml/kg per h × 24 h or anuria × 12 h
Loss (L)Persistent AKI >4 wk
ESRD (E)ESRD >3 mo
  • a AKI, acute kidney injury; RIFLE, risk, injury, failure, loss, ESRD; UO, urine output.