Early fluid accumulation in children with shock and ICU mortality: a matched case-control study

The purpose of this study was to evaluate the association between early fluid accumulation and mortality in children with shock states. We retrospectively reviewed children admitted in shock states to the pediatric intensive care unit (ICU) at a tertiary level children's hospital over a 7-month period. The study was designed as a matched case-control study. Children with early fluid overload, defined as fluid accumulation of a parts per thousand yen10 % of admission body weight during the initial 3 days, were designated as the cases. They were compared with matched controls without early fluid accumulation. Cases and controls were matched for age, severity of illness at ICU admission and need for organ support. They were compared with respect to all-cause ICU mortality and other secondary outcomes. A total of 114 children (age range 0-17.4 years; N = 42 cases and 72 matched controls) met the study criteria. Mortality rate was 13 % (15/114) in this cohort. Multivariable logistic regression analysis identified the presence of early fluid overload [adjusted odds ratio (OR) 9.17, 95 % confidence interval (CI) 2.22-55.57], its severity (adjusted OR 1.11, 95 % CI 1.05-1.19) and its duration (adjusted OR 1.61, 95 % CI 1.21-2.28) as independent predictors of mortality. Cases had higher mortality than the controls (26 vs. 6 %; p 0.003), and this difference remained significant in the matched analysis (37 vs. 3 %; p 0.002). The presence, severity and duration of early fluid are associated with increased ICU mortality in children admitted to the pediatric ICU in shock states.