Acute renal failure. Recognition and prevention.

Acute renal failure remains a devastating syndrome associated with a high mortality rate. Accurate and rapid etiologic diagnosis is critical, since it may be possible to stop the injurious process and prevent further progression of renal insufficiency. To do this, one must understand and differentiate among the three broad categories of disorders that can cause acute renal failure-prerenal, postrenal, and intrarenal processes. This article compares and contrasts these three categories in regard to causes and predisposing factors, history and physical examination, urinalysis, and urine chemistries. Treatment focuses on correcting prerenal and postrenal factors; treating acute complications, such as hyperkalemia, hyponatremia, acidosis, and pulmonary edema; optimizing cardiac output and renal blood flow; and adjusting doses of drugs consistent with renal failure.