<prompt> Which of the following values are suggestive of acute tubular necrosis :Urine osmolality500Urine sodium40Blood urea nitrogenplasma creatinine20Urine creatinine plasma creatinine40  <response>: Answer is B Urine sodium 40 Urinary sodium excretion of more than 20mmolL suggests intrinsic renal failure such as ATN Urine Diagnostic Indices: Differentiation of Prerenal and Intrinsic Renal failure. Acute tubular necrosis is a cause of Intrinsic ARF.Q 