Etiologies commonly broken into: Pre-renal, intrinsic renal or post-renal causes. Defined by change in GFR, urine output, or both. Wide range in symptoms based on acuity, other co-morbid conditions. Common sx include: fatigue, volume overload--> sob, edema, other. Though can be asymptomatic. May also have pre-existing chronic renal disease, w/AKI superimposed.
Acute kidney injury: increase in creatinine by 0.3 mg/dl in 48h; or increase in creatinine x 1.5 of baseline within 7d; or urine volume < .5 cc/kg/h for 6h