TOP 59 - Narrowing the Spectrum: Empiric Antibiotic Regimens and Clinical Outcomes in Pediatric Orbital Cellulitis

Publication Number: 1818.TOP 59

Kiera Sarill, The Children's Hospital at Montefiore, New York, NY, United States; Brenda I.. Anosike, Albert Einstein College of Medicine, Bronx, NY, United States

Background: Orbital cellulitis is a severe, potentially vision- and life-threatening bacterial infection of the post-septal orbital tissues, with an estimated 2,500 pediatric hospitalizations annually in the United States. Blood cultures are rarely positive ( < 10%) and tissue cultures are infrequently obtained, necessitating empiric management. Ampicillin/sulbactam or ceftriaxone, sometimes combined with metronidazole, clindamycin, or vancomycin, are commonly used. Although data suggest ceftriaxone monotherapy provides adequate coverage, broader-spectrum regimens remain prevalent, highlighting an opportunity for antimicrobial stewardship. Few studies have systematically examined the relationship between empiric antibiotic regimens and clinical outcomes.

Objective: The primary objective is to evaluate the association between empiric antibiotic regimens and clinical outcomes among hospitalized children with orbital cellulitis. The primary outcome was surgical intervention occurring ≥3 days after initiation of empiric antibiotics. Secondary outcomes included antibiotic escalation or broadening ≥3 days, length of stay (LOS), duration of inpatient therapy, 30-day readmission or emergency department (ED) revisits for the same diagnosis, and in-hospital mortality.

Design/Methods: This retrospective cohort study utilized data from the Pediatric Health Information System (PHIS), encompassing 47 US tertiary children’s hospitals from January 1, 2016, through June 30, 2025. Eligible patients were aged 2–21 years with an ICD-9/10 diagnosis of orbital cellulitis. Exclusion criteria included immunocompromising conditions, early surgical intervention ( < 2 days), intensive care unit admission, or hospital stay < 2 days. Empiric antibiotic regimens initiated within 48 hours of admission were categorized as: (1) ceftriaxone alone; (2) ceftriaxone plus anaerobic agent; (3) ceftriaxone plus anti-MRSA agent; (4) ceftriaxone plus anti-MRSA and anaerobic agents; and (5) ampicillin/sulbactam.

Analyses will be performed using STATA 18. Descriptive statistics will summarize demographic and clinical characteristics. Continuous variables will be analyzed using Kruskal-Wallis tests; categorical variables with Chi-square analysis, as appropriate. Multivariable logistic regression will be used to adjust for confounders. Non-inferiority of ceftriaxone monotherapy (Group 1) will be evaluated by comparing surgical rates to other regimens (Groups 2–5) with a 10% non-inferiority margin and 90% confidence interval. Data collection has been completed, and analyses will be finalized by January 31, 2026.