RIFLE is alive: long live RIFLE

Diagnosis and classification of acute kidney injury was addressed systematically only 8 years ago when the classification called RIFLE (acronym of Risk, Injury, Failure, Loss of function and End stage Kidney disease describing progressive severity of renal damage) was created. Since then, several studies have tried to apply, validate, criticize and modify this initial scheme: as a matter of fact, RIFLE is today one of the most appreciated and utilized medical classification systems worldwide. After an initial period of epidemiological research, it is acceptable to apply it now at the bedside, following both urine output and creatinine criteria, with the purpose of routinely monitoring renal function of critically ill patients.