Acute renal failure may rapidly present a life threatening situation which is amenable to appropriate medical management provided that the situation is recognized. Evidence of renal involvement may be masked by the primary medical, surgical, or obstetric condition. The pathogenesis remains controversial and inconclusive but the theories most often encountered include bakleak, tubular, obstruction, vascular obstruction, and reninangiotensin. Iscemia This tends to produce pathcy lesions affecting the proximal and distal tubular segments. Nephrotic This usually leaves the basement membrane intact while tubular destruction can range from simple cellular swelling to frank necrosis.
Damage is seenprimarily in the proximal tubulaar segments.
The influences that may bear on kidney function sare usually considered in terms of three separate but requently interrelated categories. Categories of ARF a. Prerenal Prerenal causes of renal failure act by reducing glomerular perfusion either by vasoconstriction, or a reduction of mean arterial pressure. Renal causes of ARF are due to parenchymal changes resulting from disease or nephrotoxic agents that induce renal disease. Shock and heart failure, for example, cause prerenal failure, tend to cause renal ischemia, and if allowed to progress, can produce tubular necrosis.