The presence of acute kidney injury (AKI) and fluid overload can adversely affect outcomes in children with critical illness. Continuous renal replacement therapy (CRRT) is one therapeutic modality that can improve outcomes in these patients. However, the trigger when to initiate this therapy is not known. There are studies suggesting that degree of fluid overload may be such a trigger but this does not seem to provide the entire answer. In adults, some studies have suggested that early initiation of CRRT in critically ill patients can improve outcomes compared to late initiation, although there is a paucity of evidence in children. The authors of this study sought to assess the effect timing of CRRT has on mortality in critically ill children.