Table 1.

AKIN vs. RIFLE classification for kidney injury based on serum creatinine (sCr) and/or urinary outputs (UO).

AKIN	UO (Common to Both)	RIFLE
Stage 1 Increase of ≥ 0.3 mg/dl or increase in more than or equal to 150–200% from baseline.	Less than 0.5 mg/kg/L per hour for more than 6 h	Risk Increase in sCr × 1.5 or GFR decrease >25%
Stage 2 Increase to more than 200–300% from baseline.	Less than 0.5 mg/kg/L per hour for more than 12 h	Injury sCr × 2 or GFR decrease >50%
Stage 3 Increased to more than 300% from baseline with an acute increase of at least 0.5 mg/dL or on RRT.	Less than 0.3 mg/kg/L for 24 h or anuria for 12 h	Failure sCr × 3 or >4 mg/dL with an acute rise >0.5 mg/dL or GFR decrease >75%
		Loss Persistent acute kidney failure = complete loss of kidney function >4 weeks
		End-Stage Kidney Disease ESKD >3 months

AKIN, Acute Kidney Injury Network; ESKD, end-stage kidney disease; GFR, glomerular filtration rate; sCr, serum creatinine; RIFLE, risk, injury, failure, loss, and end stage; RRT, renal replacement therapy.