Table 1.
Classifications of acute kidney injury (per guideline recommendations) [7,8,13,14]. Table adapted with permission from Gameiro, J.; Agapito Fonseca, J., Jorge, S. et al., 2018 [13].
| Class/Stage | SCr/GFR | UO | ||||
|---|---|---|---|---|---|---|
| RIFLE | AKIN | KDIGO | RIFLE | AKIN | KDIGO | |
| Risk/1 * | ↑ SCr × 1.5 or ↓ GFR > 25% | ↑ SCr ≥ 26.5 μmol/L (≥0.3 mg/dL) or ↑ SCr ≥ 150 to 200% (1.5–2X) | ↑ SCr ≥ 26.5 μmol/L (≥0.3 mg/dL) or ↑ SCr ≥ 150 to 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/2 * | ↑ SCr × 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/3 * | ↑ SCr × 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% or SCr to 353.6 μmol/L (>4 mg/dL) or initiation of renal replacement therapy | ↑ SCr > 300% 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) or GFR < 35 mL/min/1.73 m2 in patients younger than 18 years |
Abbreviations: 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; mmol/L: micromoles/liter; mg/dL:milligrams/deciliter; mL/kg/h: milliliters/kilogram/hour; h: hours. * indicates: Risk class (RIFLE) corresponds to stage 1 (AKIN and KDIGO), Injury class (RIFLE) corresponds to stage 2 (AKIN and KIDGO), and Failure class (RIFLE) corresponds to stage 3 (AKIN and KDIGO), ↑ increase, ↓ decrease.