Postoperative outcomes following institutional antibiotic protocol changes in complicated pediatric appendicitis.

INTRODUCTION: Complicated pediatric appendicitis carries substantial morbidity, including intra-abdominal abscess formation, surgical reintervention, and prolonged hospitalization. Empirical antibiotic therapy is a core component of management, yet when compared with disease severity its relative contribution to outcomes is poorly characterized in institutional practice settings. METHODS: This retrospective before-after observational study was conducted at a tertiary hospital in Bogotá, Colombia. Pediatric patients with complicated appendicitis were compared across two sequential first-line empirical antibiotic protocol periods: amikacin plus metronidazole (period 1) changed to ampicillin-sulbactam (period 2). A multivariable logistic regression model was used to identify factors associated with intra-abdominal abscess formation. RESULTS: A total of 220 patients were included (period 1, n=117; period 2, n=103). Despite differences in disease severity between periods, management during period 2 was not associated with intra-abdominal abscess formation (OR=0.72; 95% CI 0.34 to 1.51; p=0.384) or with individual secondary outcomes. Generalized peritonitis was the dominant predictor of abscess formation (OR=3.13; 95% CI 1.48 to 6.62; p=0.003). CONCLUSIONS: No differences in postoperative outcomes were observed between institutional antibiotic protocol periods. Disease severity, particularly generalized peritonitis, was the main factor associated with intra-abdominal abscess formation. These findings support prioritizing early severity assessment and source control over modifications in empirical antibiotic selection.