Table 1 Definition and classification/staging system for acute kidney injury (AKI)*.

AKI stage I

Increase of serum creatinine by

≥ 0.3 mg/dl (≥ 26.4 μmol/L)

or

increase to ≥ 150% – 200% from baseline

Urine output < 0.5 ml/kg/hour for > 6 hours

AKI stage II

Increase of serum creatinine to

> 200% – 300% from baseline

Urine output < 0.5 ml/kg/hour for > 12 hours

AKI stage III

Increase of serum creatinine to

> 300% from baseline

or

serum creatinine ≥ 4.0 mg/dl

(≥ 354 μmol/L) after a rise of at least 44 μmol/L

or

treatment with renal replacement therapy

Urine output < 0.3 ml/kg/hour for > 24 hours

or

anuria for 12 hours