Table 1.

RIFLE (Risk, Injury, Failure, Loss, End-stage kidney disease) criteria for the definition of acute kidney injury

RIFLE category	GFR criteria	Urine output criteria
Risk	Increased serum creation × 1.5 or decreased of GFR >25%	Urine output <0.5 mL/kg/hr for 6 hrs
Injury	Increased serum creatinine × 2 or decrease of GFR >50%	Urine output <0.5 mL/kg/hr for 12 hrs
Failure	Increased serum creatine × 3 or decrease of GFR >75% or serum creatinine ≥ 4 mg/dL	Urine output <0.3 mL/kg/hr for 12 hrs or anuria for 12 hrs
Loss End-stage kidney disease	Complete loss of renal function for >4 wks Need for RRT for >3 mos.

GFR, glomerular filtration rate; RRT, renal replacement therapy.