<prompt> Plasma urea creatinine ratio of 20:1 may be seen in-RhabdomyolysisUreteric calculiPre-renal failureChronic glomerulonephritis  <response>: Background. A blood urea nitrogen BUNcreatinine ratio BCR 20 0.081 in international unit is used to distinguish pre-renal azotemia PRA and acute tubular necrosis ATN. However, there is little evidence that BCR can distinguish between these two conditions andor is clinically useful Ref Harrison20th edition pg 299 