Association between fluid overload and mortality in pediatric intensive care unit

Purpose: In this study, the relationship between early, peak, and cumulative fluid overload with mortality and morbidity in patients admitted to the pediatric intensive care unit were investigated. Method: For this purpose, the data from Akdeniz University Pediatric Intensive Care Unit between January 2019 and September 2021 through the hospital registry system were collected and evaluated. The fluid overloads, which developing in the first 24 hours was defined as 'early fluid overload', the highest daily value developing in any of the first 3 days was defined as 'peak fluid overload', and the total of the first 3 days was described as 'cumulative fluid overload'. In order to show its relationship with mortality, the fluid overload was statistically evaluated in two different types such as categorical (with 5% of body weight for early and peak fluid overload, and 10% for cumulative fluid overload) and a continuous variable. Results: It was seen that 68 (11.7%) of 581 patients included in our study died. When fluid overloads were examined in terms of mortality, the percentage of early fluid overload was 1.86 and 3.35, the percent of peak fluid overload was 2.87 and 5.54, and the percent of cumulative fluid overload was 3.40 and 8.16, respectively, in the survivor and the non-survivor groups. After adjustment for age, severity of illness, and other potential confounders, peak (Adjusted Odds ratio=1.15; 95%CI 1.05-1.26; p:0.002) and cumulative (AOR=1.10; 95%CI 1.04-1.16; p<0.001) fluid overloads were determined as independent risk factors associated with mortality. The cut-off value for the peak fluid overload was 5.05% (AUC: 0.731 95%CI; 0.66-0.80 p<0.001 Cut-off: 5.05 Sensitivity: 51% Specificity: 85%). The cut-off value calculated for the cumulative fluid overload was 7.58% (AUC:0.725 95%CI; 0.65-0.80 p<0.001 Cut-off:7.58 Sensitivity:51% Specificity:89%). When the cumulative fluid overload is 10% or more, a 3.97-fold increase mortality rate was calculated. It is found that the peak and cumulative fluid overload, had significant negative correlation with intensive care unit free days (ICUfree days) and ventilator free days (VFDs). Conclusion: As a result, it is found that peak and cumulative fluid overload in critically ill children were independently associated with intensive care unit mortality and morbidity. Keywords: fluid overload, pediatric intensive care unit, mortality, acute kidney injury, sepsis, acute respiratory distress syndrome, diuretic