46 Association of Empiric Antibiotic Selection on Clinical Outcomes in Hospitalized Children with Severe Orbital Infections: A Multicenter Cohort Study

Background Antibiotic selection in children with periorbital and orbital infections is often empiric and regimens vary widely among institutions in their spectrum and inclusion of anti-anaerobic and anti-staphylococcal agents. Objectives Currently, there are no national clinical guidelines for antibiotic selection and no studies comparing commonly used antibiotic regimens in orbital infections. We aimed to determine the association of initial empiric antibiotic regimens with clinical outcomes in children hospitalized with severe orbital infections. Design/Methods We conducted a multicentre cohort study of children with severe orbital infections admitted to ten hospitals between January 1, 2009, and December 31, 2018. The association between empiric antibiotic regimen in the first 24 hours of hospitalization with length of stay and surgical intervention were assessed with multivariable median regression and multivariate logistic regression, respectively. Results Of 1421 patients, 60.0% were male, and mean age was 6.4 years (SD 4.5). Median length of stay was 86.4 hours (IQR 56.9-137.5) and 180 (12.7%) received surgical intervention. The most frequently (23.6%) administered empiric regimen consisted of a third-generation cephalosporin, anaerobic agent, and staphylococcal agent. After adjustment, broad-spectrum empiric antibiotic regimens with dedicated anti-anaerobic and/or staphylococcal coverage were associated with increased length of stay, ranging from an additional 18.4 hours (95% CI, 6.82, 30.0) to 21.5 hours (95% CI, 11.0, 32.0). Only patients with staphylococcal coverage alone had a statistically significant increased odds of surgical intervention (4.45, 95% CI 1.03, 19.2). Conclusion In children hospitalized with severe orbital infections, broad-spectrum therapy with or without coverage for staphylococci and anaerobes were associated with similar clinical outcomes in a clinical setting with low methicillin-resistant Staphylococcus aureus prevalence. Clinical practice guidelines are needed to standardize antibiotic recommendations.