Objective
In pediatric patients fluid overload (FO) at continuous renal replacement (CRRT) initiation is associated with increased mortality. The aim of this study was to characterize the association between fluid overload at CRRT initiation, fluid removal during CRRT, the kinetics of fluid removal and mortality in a large pediatric population receiving CRRT while on extracorporeal membrane oxygenation (ECMO).
Design
Retrospective chart review.
Setting
Tertiary children’s hospital
Patients
ECMO patients requiring CRRT from July 2006 to September 2010
Interventions
None
Measurements and Main Results
Overall ICU survival was 34% for 53 patients that were initiated on CRRT while on ECMO during the study period. Median FO at CRRT initiation was significantly lower in survivors compared to non-survivors (24.5 vs. 38%, p=0.006). Median FO at CRRT discontinuation was significantly lower in survivors compared to non-survivors (7.1 vs. 17.5%, p=0.035). After adjusting for percent FO at CRRT initiation, age and severity of illness, the change in FO at CRRT discontinuation was not significantly associated with mortality (p=0.212). Models investigating the rates of fluid removal in different periods, age, severity of illness and fluid overload at CRRT initiation found that fluid overload at CRRT initiation was the most consistent predictor of survival.
Conclusions
Our data demonstrates an association between FO at CRRT initiation and mortality in pediatric patients receiving ECMO. The degree of FO at CRRT discontinuation is also associated with mortality, but appears to reflect the effect of FO at initiation. Furthermore, correction of FO to ≤ 10% was not associated with improved survival. These results suggest that intervening prior to the development of significant FO may be more clinically effective than attempting fluid removal after significant fluid overload has developed. Our findings suggest a role for earlier initiation of CRRT in this population, and warrant further clinical studies.