Less Is More?—A Feasibility Study of Fluid Strategy in Critically Ill Children With Acute Respiratory Tract Infection

Abstract

Background: Fluid overload is common in critically ill children and is associated with adverse outcome. Therefore, restricting fluid intake may be beneficial. This study aims to study the feasibility of a randomized controlled trial (RCT) comparing a conservative to a standard, more liberal, strategy of fluid management in mechanically ventilated pediatric patients with acute respiratory tract infection (ARTI). Methods: This is a feasibility study in a single, tertiary referral pediatric intensive care unit (PICU). Twenty-three children receiving mechanical ventilation for ARTI, without ongoing hemodynamic support, admitted to the PICU of the Emma Children's Hospital/Amsterdam UMC between 2016 and 2018 were included. Patients were randomized to a conservative (<70% of normal intake) or standard (>85% of normal intake) fluid strategy, which was kept throughout the period of mechanical ventilation. Results: Primary endpoints were adherence to fluid strategy and safety parameters such as calorie and protein intake. Secondary outcomes were cumulative fluid intake (CFI) and cumulative fluid balance (CFB) on day 3. In the conservative group, in 75% of the mechanical ventilation days patients achieved their target fluid intake. Median [25th−75th percentiles] calorie intake over all mechanical ventilation days was 67.9 [51.5-74.0] kcal/kg/day in the conservative vs. 67.2 [58.0-75.2] kcal/kg/day in the standard group (p = 0.878). Protein intake was 1.6 [1.3-1.8] gr protein/kg in the conservative and 1.5 [1.2-1.7] gr protein/kg in the standard group (p = 0.598). No adverse effects on hemodynamics or electrolyte imbalances were noted. Mean (±SD) CFI on day 3 was 262.3 (±58.9) ml/kg in the conservative group vs. 360.5 (±52.6) ml/kg in the standard fluid group (p < 0.001), which did not result in a lower CFB. Conclusions: A conservative fluid strategy in mechanically ventilated children with ARTI seems feasible, without limiting metabolic needs. However, in our study a conservative

Current Practice of Fluid Maintenance and Replacement Therapy in Mechanically Ventilated Critically Ill Children: A European Survey

“…Second, there are questions related to timing, type and aggressiveness of interventions (e.g., fluid restriction, diuretic medication, CRRT) in a conservative fluid treatment arm complicating trial design ( 32 ). The ability to actually avoid fluid accumulation in critically ill children may be limited ( 5 ). This might require aggressive fluid restriction protocols directly following the resuscitation phase.…”

“…This sample size would rise to above 6,000 patients for a trial including all critically ill children (also non-ARDS), in order to be able to detect a significant reduction in mortality, providing the case fatality of 3.1% ( 7 ). Such numbers are unrealistic for pediatric critical care research, and thus focus should lie on alternative primary outcomes such as duration of mechanical ventilation, as well as effects on a specific sub-groups of PICU patients ( 5 ).…”

“…Restricting the amount of fluids is a daily clinical challenge, particularly in critically ill children undergoing invasive mechanical ventilation. Specifically, because the administration of fluid is necessary to provide hemodynamic support and to ensure appropriate caloric/protein intake while at the same time it functions as a vehicle for drug delivery (fluid creep) ( 5 , 6 ). As a result, a positive (cumulative) fluid balance and the formation of edema are very common in these children ( 3 , 4 , 7 , 8 ).…”

Fluid management in hospitalized pediatric patients

“…Preterm neonates have greater insensible losses compared with term newborns (40 vs 20–30 ml/kg/day, respectively), whereas children and adolescents have the least insensible losses (20 ml/kg/day and 400 ml/m 2 , respectively) 101 . Insensible fluid losses increase with febrile illness and decrease with mechanical ventilation 102 …”

“…101 Insensible fluid losses increase with febrile illness and decrease with mechanical ventilation. 102 Potassium intake should also be limited or avoided when providing IVF for children with oliguric CKD, especially in those with advanced CKD (stages 3-5) or receiving intermittent hemodialysis. The Kidney Disease Outcomes Quality Initiative (KDOQI) recommends restricting enteral potassium intake to 30-40 mg/kg/day (up to 40-120 mg in infants and younger children with CKD, and up to 2-3 g/day for older children and adolescents).…”