Table 1.

RIFLE (Risk, Injury, Failure, Loss of kidney function and End-stage kidney disease) classification and the AKIN Modification of the RIFLE classification.

RIFLE CLASSIFICATION
Class	Clinical picture
Risk	1.5-fold serum creatinine OR 25% GFR OR UO <0.5 ml/kg/h for 6 h
Injury	2-fold serum creatinine OR 50% GFR OR UO <0.5 mL/kg/h for 12 h
Failure	3-fold serum creatinine OR 75% GFR OR UO <0.3 mL/kg/h for 24 h OR no urine output for 12 h
Loss of kidney function	Complete loss of kidney function (>4 weeks)
End-stage kidney disease	Complete loss of kidney function (>3 months)
AKIN MODIFICATION
Absolute serum creatinine 0.3 mg/dL or more (>26.4 μmol/L)
OR
1.5-fold baseline serum creatinine
OR
Oliguria <0.5 mL/kg/h for >6 h; reduction in urine output