Table 3.

—AKIN Criteria for AKI

Stage	Serum Creatinine Criteria	Urine Output Criteria
1	Increase in serum creatinine ≥ 0.3 mg/dL or > 1.5- to 2-fold increase from  baseline serum creatinine	< 0.5 mL/kg/h for > 6 h
2	> 2- to 3-fold increase from baseline serum creatinine	< 0.5 mL/kg/h for > 12 h
3	> 3-fold increase from baseline serum creatinine or an absolute increase of ≥ 0.5 mg/dL in serum creatinine or the need for RRT	< 0.3 mL/kg for 24 h or anuria for 12 h

This classification schema, which followed the RIFLE system, is to be applied over a discrete 48-h period and accounts for an absolute change in serum creatinine rather than relying solely on percentage change. The AKIN criteria also permit the evaluation of urine output but do not include GFR in their definitions. AKIN = Acute Kidney Injury Network. See Table 1 and 2 legends for expansion of other abbreviations.