RIFLE classification of acute kidney injury (AKI)

 Stage I (Risk)

• Increase S. creatinine ≥ 1.5  fold from the baseline
• GFR decrease > 25%
• Urine output < 0.5 ml/kg/hr for > 6 hrs

Stage II (Injury)

• Increase S. creatinine > 2 fold from the baseline 
• GFR decrease > 50%
• Urine output < 0.5 ml/kg/hr for > 12 hrs 

Stage III (Failure)

• Increase S. creatinine > 3 fold from the baseline
• S. creatinine ≥ 4 mg/dl with acute rise of ≥ 0.5 mg/dl 
• GFR decrease > 75%
• Urine output < 0.3 ml/kg/hr for 24 hrs or anuria for 12 hrs 

Stage IV (Loss)

• Complete loss of renal function for > 4 wks 

Stage V (ESRD)

• Complete loss of renal function for > 3 months