Fluid Accumulation in Critically Ill Children*

Objectives: To describe the characteristics of fluid accumulation in critically ill children and evaluate the association between the degree, timing, duration, and rate of fluid accumulation and patient outcomes. Design: Retrospective cohort study. Setting: PICUs in Alberta, Canada. Patients: All children admitted to PICU in Alberta, Canada, between January 1, 2015, and December 31, 2015. Interventions: None. Measurements and Main Results: A total of 1,017 patients were included. Fluid overload % increased from median (interquartile range) 1.58% (0.23-3.56%;n= 1,017) on day 1 to 16.42% (7.53-27.34%;n= 111) on day 10 among those remaining in PICU. The proportion of patients (95% CI) with peak fluid overload % greater than 10% and greater than 20% was 32.7% (29.8-35.7%) and 9.1% (7.4-11.1%), respectively. Thirty-two children died (3.1%) in PICU. Peak fluid overload % was associated with greater PICU mortality (odds ratio, 1.05; 95% CI, 1.02-1.09;p= 0.001). Greater peak fluid overload % was associated with Major Adverse Kidney Events within 30 days (odds ratio, 1.05; 95% CI, 1.02-1.08;p= 0.001), length of mechanical ventilation (B coefficient, 0.66; 95% CI, 0.54-0.77;p< 0.001), and length of PICU stay (B coefficient, 0.52; 95% CI, 0.46-0.58;p< 0.001). The rate of fluid accumulation was associated with PICU mortality (odds ratio, 1.15; 95% CI, 1.01-1.31;p= 0.04), Major Adverse Kidney Events within 30 days (odds ratio, 1.16; 95% CI, 1.03-1.30;p= 0.02), length of mechanical ventilation (B coefficient, 0.80; 95% CI, 0.24-1.36;p= 0.005), and length of PICU stay (B coefficient, 0.38; 95% CI, 0.11-0.66;p= 0.007). Conclusions: Fluid accumulation occurs commonly during PICU course and is associated with considerable mortality and morbidity. These findings highlight the need for the development and evaluation of interventional strategies to mitigate the potential harm associated with fluid accumulation.