A systematic review of RIFLE criteria in children, and its application and association with measures of mortality and morbidity.

The RIFLE criteria were developed to improve consistency in the assessment of acute kidney injury. The high face validity, collaborative development method, and validation against mortality have supported the widespread adoption of the RIFLE to evaluate adult patients; however, its inconsistent application in adult studies is associated with significant effects on the estimated incidence of acute kidney injury. As the RIFLE criteria are now being used to determine acute kidney injury in children, we conducted a systematic review to describe its application and assess associations between the RIFLE and measures of mortality and morbidity in pediatric patients. In 12 studies we found wide variation in the application of the RIFLE, including the range of assessed RIFLE categories, omission of urine output criteria, varying definitions of baseline renal function, and methods for handling missing baseline measurements. Limited and conflicting associations between the RIFLE and mortality, length of stay, illness severity, and measures of kidney function were found. Thus, although the RIFLE was developed to improve the consistency of defining acute kidney injury, there are still major discrepancies in its use in pediatric patients that may undermine its potential utility as a standardized measure of acute kidney injury in children.