of Ischemic Acute Renal Failure

Acute renal failure (ARF) is a syndrome characterized by anabrupt and reversible kidney dysfunction. The spectrum ofinciting factors is broad: from ischemic and nephrotoxic agents to a variety of endotoxemic states and syndrome of multiple organ failure. The pathophysiology of ARF includes vascular, glomerular and tubular dysfunction which, depending on the actual offending stimulus, vary in the severity and time of appearance. Hemodynamic compromise prevails in cases when noxious stimuli are related to hypotension and septicemia, leading to renal hypoperfusion with sec-ondary tubular changes (described in Chapter 13). Nephrotoxic offenders usually result in primary tubular epithelial cell injury, though endothelial cell dysfunction can also occur, leading to the eventual cessation of glomerular filtration. This latter effect is a con-sequence of the combined action of tubular obstruction and activation of tubuloglomerular feedback mechanism. In the following pages we shall review the existing concepts on the phenomenology of ARF including the mechanisms of decreased renal perfusion and failure of glomerular filtration, vasoconstriction of renal arterioles, how formed elements gain access to the renal parenchyma, and what the sequelae are of such an invasion by primed leukocytes