Do Balanced Fluids Help Critically Ill Children?

April 28, 2022

Written by Rebecca Breed

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There is some evidence that bolus treatment in critically ill pediatric patients (28 days old to 18 years old) with balanced fluids (such as LR) versus unbalanced fluids (such as NS) results in improved serum bicarbonate and blood pH values. However, it’s not clear if this is clinically beneficial.

Why does this matter?
Bolus fluid therapy is one of the most commonly ordered interventions in critically ill pediatric patients. There has been longstanding debate over which fluid choice is the best, and often it is provider preference. Balanced fluids may be more expensive and less available in emergency departments. What’s the ideal fluid for bolus therapy in this patient population?

Should you put a ring(er) on it?
This study was both a systematic review and meta-analysis. Primary outcome in the meta-analysis was the mean change in serum bicarbonate or serum pH within 24 hours of bolus fluid therapy. There were 13 references that met criteria and were reviewed (RCTs and observational studies), though only 3 RCTs were sufficient for inclusion in the meta-analysis after bias analyses. This led to a population of 162 patients. Bolus treatment was defined as a minimum of 20 mL/kg or 1 L cumulative. In the trials included, serum bicarbonate levels were higher in the balanced fluids group with a difference in mean change of 1.6 mmol/L (95%CI 0.04 to 3.16, p=0.04) and pH levels were higher in the balanced fluid group with mean difference of 0.03 (95%CI 0.00 to 0.06, p=0.03). The authors note their intended primary outcome was the prevalence and/or time to resolution of metabolic acidosis; however, data was not sufficient for this outcome. Instead, this was a secondary outcome along with prevalence of hyperchloremia (Cl > 106 mmol/L), AKI within 48 hours, need and/or duration of RRT, duration of vasopressors, duration of mechanical ventilation, total volume or rehydration needed per day, need for ECMO, ICU and hospital LOS, and mortality. There was no identified significant difference between the two groups in terms of these secondary outcomes. Authors noted that the study was limited by small sample size and risk of high bias in some of the included studies and recommend further evaluation with additional RCTs.

Editor’s note: This change in pH is approximately the same difference seen between an arterial blood gas (ABG) and a venous blood gas (VBG), which is widely considered trivial. ~Nick

Source
Balanced Versus Unbalanced Fluid in Critically Ill Children: Systematic Review and Meta-Analysis. Pediatr Crit Care Med. 2022 Mar 1;23(3):181-191. doi: 10.1097/PCC.0000000000002890.