Ellison DH, Bia MJ. Acute renal failure in critically ill patients. J Intensive Care Med 1987;2:8-24.Acute renal failure is an important cause of morbidity in critically ill patients. Acute renal failure results from prerenal and postrenal causes and, most importantly, acute tubular necrosis (ATN). Although it is known that renal toxins and renal ischemia are the most common causes of ATN in hospitalized patients, the exact pathogenesis of this entity is still not fully understood. Patients in the intensive care unit are at high risk for ATN because of hemodynamic instability, the administration of nephrotoxic antibiotics or chemotherapeutic agents, and exposure to radiographic contrast agents. The acquired immunodeficiency syndrome is also associated with an increased risk of renal failure development, either from complications of the disease itself or from its treatment. Many consequences of acute renal failure such as volume overload, acidosis, hyperkalemia, and serositis can be managed adequately with peritoneal dialysis, hemodialysis, or a newer technique, continuous arteriovenous hemofiltration. Despite improvements in treatment, however, the mortality of ATN remains high. In this review, we recommend measures to prevent ATN in certain clinical situations that commonly occur among critically ill patients. We also review therapeutic options for treating patients in whom acute renal failure develops and discuss newer developments that may begin to reduce the excessive morbidity associated with ATN.In its broadest sense acute renal failure refers to an abrupt (days to weeks) decrement in glomerular filtration rate (GFR) from any cause. Acute renal failure occurs in approximately 5% of all admissions to medical and. surgical wards in general hospitals [1]. The frequency of this complication is even higher, between 10 and 20%, in critically ill patients and in those admitted to intensive care units (ICUs) [2][3][4][5]. The most common causes of acute renal failure in a modern hospital setting include prerenal azotemia and acute tubular necrosis (ATN) resulting from decreases in renal perfusion or administration of nephrotoxic drugs. Renal ischemia may occur because of shock, operation, sepsis, burns, or decreased true or effective intravascular volume. Although hypotension is common in these settings, operation, sepsis, and burns may cause renal ischemic damage even without a measurable lowering of systemic blood pressure [1]. The leading causes of nephrotoxin-induced acute renal failure include the administration of radiographic contrast media and antibiotics, especially the aminoglycosides. In one study of 129 patients [1], renal ischemia and nephrotoxin administration caused 79% of hospital acquired acute renal failure. Iatrogenic factors, broadly defined as surgery, volume contraction, or the administration of nephrotoxins, accounted for over half (55%) of all episodes. For patients in an ICU, shock, sepsis, and operation, especially for abdominal aortic aneurysms, constitute the most common precipitating fa...