<prompt> Which of the following is NOT a feature of pre renal azotemia?BUNPCr ratio 20:1Urine sodium UNa, meqL 20Urine osmolality, mosmolL H2O 500Urineplasma creatinine UCrPCr 20  <response>: Urineplasma creatinine UCrPCr will be 40 in pre renal azotemia. Difference between pre renal and and acute tubular necrosis: Pre renal failure FENa is less than 1 Urine Na is less than 20mmoll Urine osmolality is more than 500mosmkg Fractional excretion of BUN is less than 35 BUNCreatinine ratio is more than 20:1 Acute tubular necrosis FENa is more than 2 Urine sodium is more than 30 mmoll Urine osmolarity is less than 350mosmkg BUNCreatinine ratio is less than 10:1 Ref: Harrisons principles of internal medicine, 18th edition, Page 337 