Table 1 The definitions and classification for AKI.
| Â | SCr criteria | UO Criteria |
|---|---|---|
(A) RIFLE | ||
 Definition | SCr changes over 1–7 days, sustained for more than 24 hrs | UO < 0.5 ml/kg/h x 6 hrs |
 Risk | Increase in SCr ≥ 1.5 x baseline or decrease in GFR ≥ 25% | UO < 0.5 ml/kg/h x 6 hrs |
 Injury | Increase in SCr ≥ 2.0 x baseline or decrease in GFR ≥ 50% | UO < 0.5 ml/kg/h x 12 hrs |
 Failure | Increase in SCr ≥ 3.0 x baseline or an absolute serum creatinine ≥4.0 mg/dl with an acute rise of at least 0.5 mg/dl or or decrease in GFR ≥ 75% | UO < 0.5 ml/kg/h x 24 hrs or anuria x 12hrs |
 Loss | Complete loss of kidney function > 4 wks |  |
 ESRD | End-stage renal disease (>3 mo) |  |
(B) AKIN | ||
 Definition | Acute SCr changes occur within a 48 hrs period during hospitalization | Same as RIFLE |
 Stage 1 | Increased in SCr of ≥0.3 mg/dl or increase to 1.5–1.9 x baseline |  |
 Stage 2 | Increase in SCr to 2.0–2.9 x baseline |  |
 Stage 3 | Increase in SCr ≥ 3.0 x baseline or SCr ≥ 4.0 mg/dl with an acute rise of at least 0.5 mg/dl or Initiation of RRT |  |
(C) KDIGO | ||
 Definition | SCr changes ≥ 1.5 x baseline to have occurred within the prior 7 days or a 0.3 mg/d lincrease in SCr must occur within a 48 hrs period | Same as RIFLE |
 Stage 1 | Increased in SCr ≥ 1.5 x baseline or of 0.3 mg/dl |  |
 Stage 2 | Increase in SCr ≥ 2.0 x baseline |  |
 Stage 3 | Increase in SCr ≥ 3.0 x baseline or increase in serum creatinine to ≥ 4.0 mg/dl or initiation of RRT |  |
