1) Perioperative acute renal failure occurs in up to 30% of cardiac surgery patients and 1-7% of aortic surgery patients, with mortality over 40%. Acute tubular necrosis is the most common cause. 2) Risk factors include preexisting renal insufficiency, older age over 60, and left ventricular dysfunction. General preventative measures include optimizing hemodynamics, avoiding nephrotoxins, and using isosmolar contrast. 3) Pharmacologic interventions studied to prevent renal failure include fenoldopam, atrial natriuretic peptide, mannitol, and N-acetylcysteine, though evidence is limited. Continuous renal replacement therapy may benefit critically ill