serena fallure Hypovolemia, Acute heart failure Expanded vascular bed volume Sudden decrease of (Hepatorenal syndrome renal perfusion Anaphylactic shock, etc.) Renal vascular blockage or GORI auto-regulation disturbances Nat, H2O reabsorption Azotemia(urinary Cr/plasma Cr> 40) Oliguna(<400ml/day) Urinary Nat<20 mmol/L Urine gravity >1.020 No rbC. WbC or cast in urine 1919 Sudden decrease of renal perfusion Hypovolemia, Acute heart failure Expanded vascular bed volume (Hepatorenal syndrome Anaphylactic shock, etc. ) Renal vascular blockage or auto-regulation disturbances ( l ) Prerenal failure Azotemia(urinary Cr/plasma Cr > 40 ) Oliguna (<400ml/day) Urinary Na+<20 mmol/L Urine gravity > 1.020 No RBC, WBC or cast in urine GFR↓ Na+ , H2O reabsorption↑