Table 1.
Risk, Injury, Failure, Loss of kidney function, End-stage kidney disease (RIFLE) [35], Acute Kidney Injury Network (AKIN) [36], and kidney disease improving global outcomes (KDIGO) [37] classifications
| Class/stage | SCr/GFR | UO | ||||
|---|---|---|---|---|---|---|
| RIFLE | AKIN | KDIGO | RIFLE | AKIN | KDIGO | |
| Risk/1a | ↑ SCr X 1.5 or ↓ GFR > 25% | ↑ SCr ≥ 26.5 μmol/l (≥ 0.3 mg/dl) or ↑ SCr ≥ 150–200% (1.5–2X) | ↑ SCr ≥ 26.5 μmol/l (≥ 0.3 mg/dl) or ↑ SCr ≥ 150–200% (1.5–2X) | <0.5 ml/kg/h (> 6 h) | <0.5 ml/kg/h (> 6 h) | <0.5 ml/kg/h (> 6 h) |
| Injury/2a | ↑ SCr X 2 or ↓ GFR > 50% | ↑ SCr > 200–300% (> 2–3X) | ↑ SCr > 200–300% (> 2–3X) | <0.5 ml/kg/h (> 12 h) | <0.5 ml/kg/h (> 12 h) | <0.5 ml/kg/h (> 12 h) |
| Failure/3a | ↑ SCr X 3 or ↓ GFR > 75% or if baseline SCr ≥ 353.6 μmol/l (≥ 4 mg/dl) ↑ SCr > 44.2 μmol/l (> 0.5 mg/dl) | ↑ SCr > 300% (> 3X) or if baseline SCr ≥ 353.6 μmol/l (≥ 4 mg/dl) ↑SCr ≥ 44.2 μmol/l (≥ 0.5 mg/dl) or initiation of renal replacement therapy | ↑ SCr > 300% (> 3X) or ↑SCr to ≥ 353.6 μmol/l (≥ 4 mg/dl) or initiation of renal replacement therapy | <0.3 ml/kg/h (> 24 h) or anuria (> 12 h) | <0.3 ml/kg/h (24 h) or anuria (12 h) | <0.3 ml/kg/h (24 h) or anuria (12 h) |
SCr serum creatinine, GFR glomerular filtration rate, UO urine output, RIFLE Risk, Injury, Failure, Loss of kidney function (dialysis dependence for at least 4 weeks), End-stage kidney disease (dialysis dependence for at least 3 months), AKIN Acute Kidney Injury Network, KDIGO kidney disease improving global outcomes
aRisk class (RIFLE) corresponds to stage 1 (AKIN and KDIGO), injury class (RIFLE) corresponds to stage 2 (AKIN and KDIGO), and failure class (RIFLE) corresponds to stage 3 (AKIN and KDIGO)