Lab values for prerenal vs intrinsic vs postrenal
Prerenal-Urine osmolarity: >500 (parenchyma is fine and thus water is able to be reabsorbed)-Urine Na: <20-FeNa: <1%-Serum BUN/Cr > 20 (parenchyma is fine and thus BUN is able to be reabsorbed)Intrinsic/late postrenal–Urine osmolarity: <350-Urine Na: >40-FeNa: >2%-Serum BUN/Cr < 15