Staging of acute kidney injury	Stage 1	Stage 2	Stage 3
‐	Increase in serum creatinine ≥ 0.3 mg/dL (≥ 26.5 μmol/L) or an increase in serum creatinine ≥ 1.5‐fold to 2‐fold from baseline.	Increase in serum creatinine > 2‐fold to 3‐fold from baseline.	Increase of serum creatinine > 3‐fold from baseline or serum creatinine ≥ 4.0 mg/dL (≥ 353.6 μmol/L) with an acute increase ≥ 0.3 mg/dL (≥ 26.5 μmol/L) or initiation of renal replacement therapy.
Progression of acute kidney injury	Progression	‐	Regression
‐	Progression of acute kidney injury to a higher stage or need for renal replacement therapy, or both.	‐	Regression of acute kidney injury to a lower stage.
Response to treatment	No response	Partial response	Full response
‐	No regression of acute kidney injury.	Regression of acute kidney injury stage with a reduction of serum creatinine to ≥ 0.3 mg/dL (≥ 26.5 μmol/L) above baseline value.	Return of serum creatinine to within 0.3 mg/dL (26.5 μmol/L) of baseline value.