Scr = serum creatinine, UO = urine output
Stage 1:
Scr increase >= 27 micromol/L OR 1.5-1.9 times from baseline
UO <0.5mL/kg/hr for 6-12hr
Stage 2:
Scr increase 2-2.9 times from baseline
UO <0.5mL/kg/hr for >=12hr
Stage 3:
Scr increase >= 354 micromol/L OR 3 times from baseline OR need RRT OR eGFR <35ml/min/1.73m2
UO anuria for >=12hr