Prospective Cohort Study on Cumulative Fluid Balance and Outcome in Critically Ill Children Using a Restrictive Fluid Protocol.

Objective: To study the association of cumulative fluid balance and clinical outcomes in a pediatric intensive care unit (PICU) practicing restrictive fluid protocol.

Methods: In this prospective cohort study, children aged less than 13 y admitted for more than 48 h were screened. Children with unstable hemodynamics throughout the stay were excluded. Fluid balance was calculated by percentage fluid overload (%FO) for the first 7 d. Patients were divided into positive fluid and negative fluid balance groups. The primary outcome was all-cause 28-d mortality.

Results: A total of 888 patients (positive fluid balance group = 531, negative fluid balance group = 357) were analyzed. Mean (SD) cumulative %FO was 1.52 (0.67) vs. -1.18 (0.71), p = < 0.001, and minimum and maximum cumulative %FO were -3.0% and 3.1%, respectively. There was no significant difference in all-cause 28-d mortality between the two groups (n = 104/531, 19.6% vs. n = 60/357, 16.8%, RR = 1.17, 95% CI 0.87 to 1.55; p = 0.29). There was no difference in organ dysfunction [mean (SD) sequential organ failure assessment (SOFA) score 3.3 (0.7) vs. 3.3 (0.6)], acute kidney injury (65% vs. 63.6%), need for renal replacement therapy (14% vs. 13%), and duration of ventilation (median, IQR 4, 2-6 vs. 4, 2-6 d). Longer stay in PICU (5, 3-9 vs. 4, 3-7 d; p = 0.014) and in hospital (8, 5-11 vs. 7, 4-10 d; p = 0.007) were noted in the positive fluid balance group.

Conclusion: Cumulative fluid balance within 3% using restrictive fluid protocol was not associated with a significant difference in PICU mortality and morbidity.