**1. Introduction**

Fluid management is one of the regular aspects of care in PICU setting, and its importance has been stressed in previous studies [1]. Fluid resuscitation, as part of fluid management, may be needed to maintain intravascular volume [2], and prior studies showed that early aggressive fluid resuscitation may improve outcome in critical illness [1], especially in endothelial-dysfunction associated conditions [3]. Unfortunately, this routine management often leads to the development positive fluid balance and consequently, fluid overload (FO) [1, 3, 4]. Many evidences have stated that excessive fluid administration is closely associated with negative effects for children who were admitted in PICU [3, 4]. FO was known to cause

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

increased risk of morbidity, mortality, additional time of mechanical ventilation, additional hospitalization time, and increased need for renal replacement therapy (RRT) [5, 6].

In patients who already have critically ill also shown that fluid overload shows a negative effect. Flori et al. [2] conducted post-hoc study about the association positive fluid balance with worse clinical outcomes in children with ALI. This study showed the increment of 10 mL/kg/day fluid balance was associated with increasing mortality. Moreover, the increments were also associated with fewer ventilator-free days. Flori also suggested that fluid overload itself may be a risk factor for mortality regardless of initial presenting severity of illness [2]. In another study involving 778 patients with septic shock post resuscitation also found that fluid overload increased up to twice the mortality rate [5]. Vincent et al. [7] in their research on sepsis patients found that each addition of a positive fluid balance after 72 h was associated with an increased odds ratio of mortality by 10%. Sutawan et al. [6] study also found that fluid overload was associated with mortality (OR 11.5; 95% CI: 3.7–35.6; p < 0.001) with a range of 12.9 ± 7.9% on 120 subjects.
