Balanced Crystalloids versus Normal Saline in Children with Critical Asthma

There is little known about the impact of maintenance fluid choice in children with critical asthma on clinical outcomes. Our primary study objectives were to determine the differences in the serum chloride and bicarbonate levels based on the receipt of 0.9% saline or a balanced solution. The secondary study objectives included differences in acute kidney injury (AKI) and intensive care unit (ICU)/hospital length of stay (LOS). In this retrospective cohort study, we included 1166 patients admitted to a quaternary children's hospital with critical asthma between 2017 and 2019. The patients were stratified based on if they received 0.9% saline or a balanced solution (Lactated Ringer's or Plasma-lyte) for maintenance therapy. The study outcomes were determined using independent sample t-tests, multivariable logistic regression, and negative binomial regression. The patients who received 0.9% saline maintenance therapy had a significantly higher increase in their serum chloride levels when compared to those who received balanced solutions (0.9% saline: +4 mMol/L, balanced: +2 mMol/L, p = 0.002). There was no difference in the decrease in the serum bicarbonate levels (0.9% saline: -0.4 mMol/L, balanced: -0.5 mMol/L, p = 0.830). After controlling for age, race, sex, and the Pediatric Logistic Organ Dysfunction (PELOD-2) score, there was no association between the type of fluid received and the development of AKI (OR 0.87, 95% CI: 0.46-1.63, p = 0.678). Additionally, there was no association between the type of fluid and hospital or ICU LOS. Thus, despite higher serum chloride levels in the patients that received 0.9% saline, the choice of fluid therapy did not have an impact on the serum bicarbonate values, the development of AKI or hospital and ICU LOS, suggesting there is little difference between 0.9% saline and balanced solutions as maintenance therapy in children with critical asthma.