Acute Oliguria

THE conventional approach to the differential diagnosis of oliguria (50 to 400 ml of urine per day) focuses first on establishing the anatomic location of the initiating disturbance. Within this framework, the causes of acute oliguria can be grouped into one of three classes: inadequate renal perfusion (pre-renal or functional azotemia); obstruction (post-renal azotemia); and intrinsic renal diseases. The logic of this classification centers about the paramount importance of excluding rigorously both pre-renal and post-renal disorders, for which specific therapy is often curative, before one assumes the presence of intrinsic renal disease, for which immediate, specific treatment is only rarely . . .