Table 1.

AKI diagnostic criteria.

Staging	Urine volume	Diagnostic criteria
		RIFLE (2002)	AKIN (2005)	KIDGO (2012)
1 issue	Urine output <0.5 ml/kg/h > 6 h	Risk: sCr elevated > 1.5 times or GFR decline > 25%	sCr elevated ≥ 26.4 μmol/L or elevated > 1.5–2.0 times the baseline value	sCr elevated ≥ 26.5 μmol/L (0.3 mg/dl) or elevated > 1.5–1.9 times the baseline value
2 issues	Urine output <0.5 ml/kg/h > 12 h	Injury: sCr elevated > 2 times or GFR decline > 50%	sCr elevation > 2.0–3.0 times the baseline value	Elevation > 2.0–2.9 times the baseline value
3 issues	Urine output <0.3 ml/kg/h > 24 h or no urine for >12 h	Failure: sCr elevated > 3 times or GFR decline > 75% sCr ≥ 354 μmol/L or an acute increase of ≥ 44 μmol/L Loss: persistent renal failure > 4 weeks ESRD: persistent renal failure > 3 months	sCr elevation > 3.0 times the baseline value or sCr value ≥ 354 μmol/L or an increase in acute sCr values ≥ 44 μmol/L	sCr elevated ≥353.6 μmol/L (4 mg/dl) or elevated > 3.0 times the baseline value or starting kidney replacement therapy or <18-year-old patients with a decrease in eGFR to <35 ml/min/1.73 m2