Table 1

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

AKI stage
Creatinine criteria
Urine output criteria

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

Diagnostic criteria for AKI includes an abrupt (within 48 hours) reduction in kidney function defined as an absolute increase in serum creatinine of either 0.3 mg/dl or more (≥ 26.4 μmol/L) or a percentage increase of 50% or more (1.5 fold from baseline) or a reduction in urine output. *according to Mehta and colleagues [3]

Ostermann et al. Critical Care 2008 12:R144   doi:10.1186/cc7123