acute renal failure (ARF)

Definition :
      no precise definition for acute renal failure (ARF), characterized by an abrupt increase in serum cratinine >0.3mg/dl. within 48 hours, or a similar increase over a few weeks or months

Classification
     Oliguric or nonoliguric renal failure : based on the amount of urine output
     Cutoffs of approximately 500ml/d or 25 ml/hr for 4 hours are frequently used in clinical practice

Etiology
    devided according to the anaomic location of the physiologic defect.
        *Prerenal disease : a disturbance of renal perfusion.
        *Postrenal disease : obstruction of the urinary collecting system
        *Intrinsic renal disease :involvement of glomeruli, microvasculatory, tubules, or interstitium of the kidneys