Definition of Acute kidney injury include
AKI is currently defined by a rise of serum creatinine from baseline by at least 0.3 mg/dL within 48 h or at least 50% higher than baseline within 1 week, or a reduction in urine output to less than 0.5 mL/kg per hour for longer than 6 h. Ref: Harrison 19e pg: 1800
Increase of serum creatinine by 1mg/dl in 24 hours
BUN/Creatinine ratio above 20
Urine output less than 1000ml in a day
50% increase in baseline serum creatinine in a week
Kidney