Pre-renal azotemia is associated with one of the Mowing characteristic feature -
Ref:Harrison 20th edition pg no 291. Values pre renal Azotemia oliguric phase of renal failure BUN/p cr >20:1 10-15:1 Urine sodium meq/L <20 >40 Urine osmolality mosmol/L H20 >500 <350 Fractional excretion of Na <1% >2% Urine analysis (casts) hyaline or granular muddy brown Urine/plasma creatininr >40 <20
UrinaryNa+< lOmmol/L
Renal failure index > 1
Osmolality < 500
Urinary creatinine/P.creatinine ratio < 20
Kidney