534 - Association of Intravenous Fluid Use on Length of Stay for Patients with Bronchiolitis in the Pediatric Emergency Department

Publication Number: 2519.534

Arino Neto, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, United States; Sriram Ramgopal, Ann & Robert H. Lurie Children's Hospital of Chicago, CHICAGO, IL, United States; Douglas Lorenz, University of Louisville, Louisville, KY, United States; Jennifer K. Saper, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, United States; Anne Lakes, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, United States; Todd A. Florin, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, United States

Background: Bronchiolitis is a leading cause of emergency department (ED) visits in children under two years old. Despite guidelines discouraging unnecessary tests and treatments, resource use and hospitalization rates for children with bronchiolitis remain high. While hydration is a key tenet of bronchiolitis management, it is unclear if intravenous (IV) fluids are necessary in many patients. IV fluid use has the potential to increase hospital length of stay (LOS) and resource use, yet limited data exist on how IV fluid administration affects these parameters.

Objective: To evaluate the association between IV fluid administration and hospital LOS and resource utilization among children presenting to the ED with bronchiolitis.

Design/Methods: We conducted a retrospective cohort study using electronic health record data from a single pediatric hospital with 55,000 annual ED visits. We included children ≤23 months old with a primary or secondary diagnosis of bronchiolitis from October 31, 2023, to March 31, 2025. The primary exposure was the use of IV fluids during the encounter. The primary and secondary outcomes were LOS in hours from ED arrival to discharge and any laboratory testing (CBC, BMP, or CMP), respectively. To account for markers of severity, we performed inverse probability weighting with 3:1 nearest-neighbor matching, adjusting for demographics, comorbidities, acuity level, oxygen use, and age-adjusted vital signs to evaluate the association of IV fluid use and LOS and ancillary laboratory testing.

Results: A total of 2,462 encounters were included; 567 (23%) received IV fluids. Compared to those who did not, children given IV fluids were more likely to be premature (12% vs 6%), have congenital heart disease (12% vs 5%), be tachypneic (54 vs 44 bpm), and receive supplemental oxygen (70 vs 9%). Median LOS was significantly longer for those with IV fluids (50 vs 5 hours). After adjustment, IV fluid use remained associated with increased LOS (adjusted mean difference 49.9 hours [95% CI 29.0-70.8]) and higher laboratory utilization (adjusted OR 70.7 [95% CI 42.6-117.2]). Propensity-weighted analyses confirmed increased LOS (mean difference 19.5 hours [95% CI 17.8-21.2]) and increased laboratory utilization (OR 68.8 [95% CI 49.3-96.1]) in those receiving IV fluids.

Conclusion(s): Among children presenting to the ED with bronchiolitis, IV fluid administration was independently associated with prolonged LOS and increased laboratory utilization, even after adjusting for illness severity. IV fluids may represent a modifiable target for reducing unnecessary interventions and improving bronchiolitis care pathways.

Table 1
Baseline characteristics of the unmatched sample. Values are count (percentage) or median [Q1, Q3]

Table 2
Outcomes of propensity score-matched cohort

Image 1
Distribution of total length of stay (LOS) in hours by IV fluid administration status