Table 1.

The AKIN and RIFLE criteria for identification and staging of AKI.

AKIN criteria∗			RIFLE criteria∧
Stage	Creatinine	Urine output	Stage	Creatinine or GFR	Urine output
1	Increase of >0.3 mg/dL or 0.5–2 times (baseline)	<0.5 mg/kg/hr for >6 hr	Risk	sCr increase ×1.5 (baseline) or GFR decrease >25%	<0.5 mg/kg/hr for >6 hr
2	2-3 times (baseline)	Anuria for 12 hr or <0.5 mg/kg/hr for >12 hr	Injury	sCr increase ×2.0 (baseline) or GFR decrease >50%	<0.5 mg/kg/hr for 12 hr
3	RRT or level of 4.0 mg/dL with an acute increase of 0.5 mg/dL	<0.3 mg/kg/hr for 24 hr	Failure	sCr increase ×3.0 (baseline) or GFR decrease >75% or 4.0 mg/dL with an acute increase of 0.5 mg/dL	<0.5 mg/kg/hr for 12 hr
			Loss	Persistent AKI (loss of renal function >4 weeks)
			ESKD	End stage kidney disease >3 months

^∗Renal assessment time window up to 48 hours.

^∧Renal assessment time window up to 7 days.