[Acute renal insufficiency in children].

Acute renal failure (ARF) implies a sudden decrease in glomerular filtration rate with consequent retention of nitrogen waste products, water and electrolytes normally excreted by the kidney. The causes of ARF fall into three main groups: prerenal, intrinsic, and postrenal. Prerenal or functional failure can usually be controlled by simple therapeutic measures. If unrelieved, it leads to the development of renal parenchymal damage. Early biochemical indices are useful in distinguishing prerenal from intrinsic renal failure. Potentially reversible obstruction must be searched for by ultrasonographic and radiological procedures, and rapidly relieved. Symptoms of ARF result from disturbance of physiological regulatory functions. Prerenal failure requires urgent vascular expansion and careful monitoring of fluid and electrolyte replacement. Established renal failure demands careful management of electrolyte and water overload, metabolic acidosis, anemia, hypertension, infections and nutrition. Peritoneal dialysis or hemodialysis should be prepared for whenever severe hypertension, pulmonary edema or worsening biochemistry occur. Acute renal failure has a generally good prognosis if properly treated.