A retrospective cohort study of the ability to achieve negative water balance in critically ill children undergoing CRRT and its possible relation to mortality.

Primary research question: to investigate if the ability to achieve a negative fluid balance during the first 3 days using continuous dialysis was associated with mortality and other key outcomes in children with multiple organ failure (MOF). Background: Critically ill children with MOF are subjected to high mortality which further increase if substantial fluid overload (FO) is present. Participant characteristics: Critically ill children (0-18 years) with 3 or more organs failing, including severe acute kidney injury requiring dialysis. Median age was 4 months. Key results: Mortality during intensive care was 29 %. Survivors had less FO compared to non-survivors on dialysis initiation, 15 and 24 % respectively. The mortality was lower in patient where a negative fluid balance was achieved, as compared to patients who had further fluid accumulation, 12 vs 86 % respectively. Limitations: The main limitation is the retrospective design of the study. The results need to be verified in prospective studies.