1. James C. M. Chan, MD*† 2. Debra M. Williams, MD* 3. Karl S. Roth, MD*† 1. *Department of Pediatrics, Virginia Commonwealth University, Medical College of Virginia Campus, Richmond, VA 2. †Department of Biochemistry, Virginia Commonwealth University, Medical College of Virginia Campus, Richmond, VA After completing this article, readers should be able to: 1. Recognize and delineate the causes of acute renal failure. 2. Formulate emergency management of fluid electrolyte disorders in acute renal failure. 3. Characterize the incidence, causes, and costs of chronic renal failure in children. 4. Explain the pathogenesis and treatment of complications of chronic renal failure. 5. Delineate a plan to help the family with the outcome of renal failure. The evaluation of kidney failure is challenging, despite many advances in diagnosis and treatment over the past decade. To provide pediatricians with an informed choice, this article reviews both acute and chronic renal failure, their multiple causes, the principles of treatment, and both short- and long-term outcomes. Acute renal failure (ARF) is characterized by the abrupt failure of the kidneys to regulate water and electrolyte homeostasis. ARFs in childhood due to hemolytic-uremic syndrome, postinfectious acute glomerulonephritis, or dehydration are reversible, but a small percentage may progress to chronic renal failure (CRF). CRF is the result of slowly progressive kidney diseases and seldom is fully reversible. This condition in childhood is associated with obstructive uropathy, congenital aplastic/hypoplastic/dysplastic kidneys, and other causes. In CRF, almost every system in the body eventually becomes compromised. ### Incidence and Causes ARF is encountered in 3% to 10% of all admissions to neonatal intensive care units. In our experience with a regional pediatric nephrology program serving a catchment area of 1.5 million general population, 6.4% of 3,154 children referred to the program from community physicians suffered from ARF. However, precise figures on the true incidence of ARF in childhood are surprisingly sparse. ARF is a life-threatening, abrupt reduction of urinary output to less than 300 mL/m2 per day that is precipitated by prolonged renal ischemia in most cases. Occasionally, it may present with a high urinary output but mounting serum urea nitrogen and creatinine …