Patients will be included those of pediatric emergencies, Hospitalization Unit of Short Duration pediatric, pediatric intensive care and pediatric resuscitation. The acute renale failure will be estimated on the basis of criteria KDIGO (score of kidney disease) group in 2012 to 48 hours a computed tomography (CT) scan with injection of contrast media, based on a change in creatinine clearance of the estimated according to the formula Schwartz revised in 2009 and / or diuresis.