Association between early fluid overload and mortality in critically-ill mechanically ventilated children: a single-center retrospective cohort study

BACKGROUND: Positive fluid overload (FO) may cause adverse effect. This study retrospectively analyzed the relationship between early FO and in-hospital mortality in children with mechanical ventilation (MV) in pediatric intensive care unit (PICU). METHODS: This study retrospectively enrolled 309 children (ages 28 days to 16 years) receiving invasive MV admitted to the PICU of Xinhua Hospital from March 2014 to March 2019. Children receiving MV for less than 48 h were excluded. The FO in the first 3 days of MV was considered to the early FO. Patients were divided into groups according to early FO and survival to evaluate the associations of early FO, percentage FO(%FO) > 10%, and %FO > 20% with in-hospital mortality. RESULTS: A total of 309 patients were included. The mean early FO was 8.83 ± 8.81%, and the mortality in hospital was 26.2% (81/309). There were no significant differences in mortality among different FO groups (P = 0.053) or in early FO between survivors and non-survivors (P = 0.992). Regression analysis demonstrated that use of more vasoactive drugs, the presence of multiple organ dysfunction syndrome, longer duration of MV, and a non-operative reason for PICU admission were related to increased mortality (P < 0.05). Although early FO and %FO > 10% were not associated with in-hospital mortality (β = 0.030, P = 0.090, 95% CI = 0.995–1.067; β = 0.479, P = 0.153, 95% CI = 0.837–3.117), %FO > 20% was positively correlated with mortality (β = 1.057, OR = 2.878, P = 0.029, 95% CI = 1.116–7.418). CONCLUSIONS: The correlation between early FO and mortality was affected by interventions and the severity of the disease, but %FO > 20% was an independent risk factor for in-hospital mortality in critically ill MV-treated children.