Table 1.

Diagnostic criteria for AKI according to RIFLE, AKIN and KDIGO. RIFLE, Risk Injury Failure Loss and End-Stage Renal Failure; AKIN, Acute Kidney Injury Network; KDIGO, Kidney Disease: Improving Global Outcomes; Scr, serum creatinine; RRT, renal replacement therapy.

Class/Stage	Criterion SCr/GFR			Urine Output
	RIFLE	AKIN	KDIGO	RIFLE/AKIN/KDIGO
Risk (RIFLE)/ Stage 1 (AKIN and KDIGO)	SCr increase ×1.5 within 7 days or GFR decrease >25%	SCr increase ≥26.5 μmol/L (≥0.3 mg/dL) within 48 h or 1.5–2× within 7 days	SCr increase ≥26.5 μmol/L (≥0.3 mg/dL) within 48 h or 1.5–1.9× within 7 days	<0.5 mL/kg/h (>6 h)
Injury (RIFLE)/ Stage 2 (AKIN and KDIGO)	SCr increase ×2 or GFR decrease >50%	SCr increase 2–3×	SCr increase 2–2.9×	<0.5 mL/kg/h (>12 h)
Failure (RIFLE)/ Stage 3 (AKIN and KDIGO)	SCr increase ×3 or SCr ≥ 354 μmol/L (≥4 mg/dL) with acute rise 44 μmol/L (>0.5 mg/dL) or GFR decrease >75%	SCr increase ×3 or SCr ≥ 354 μmol/L (≥4 mg/dL) with acute rise 44 μmol/L (>0.5 mg/dL) or need for RRT	SCr increase ×3 or SCr ≥ 354 μmol/L (≥4 mg/dL) or need for RRT	<0.3 mL/kg/h (>24 h) or anuria >12 h