A standardized classification of acute kidney injury (AKI) has recently been proposed with the RIFLE (Risk, Injury, Failure, Loss of function, End-stage kidney disease) score. Such definition/classification has been applied both in adult and in paediatric patients. Neonatal definition of AKI likely results as a challenging task due to the peculiar renal pathophysiology of newborn critically ill patients. Their so-called 'immature kidneys' require careful management and neonatal AKI is frequently complicated by unfavourable outcomes. A recent attempt to implement the RIFLE score with a neonatal modification might lead to improvement on the knowledge of AKI incidence and epidemiology.
Keywords: RIFLE score; acute kidney injury; classification; definition.