Association of Postoperative Fever and Antibiotic Use with Surgical Site Infection in Children with Complicated Appendicitis: A Retrospective Cohort Study

BACKGROUND: Surgical site infection risk after pediatric complicated appendicitis remains difficult to predict, driving variable discharge antibiotic prescribing. We evaluated whether postoperative day (POD) 3 or 4 fever stratifies surgical site infection risk and whether discharge antibiotics are associated with lower post-discharge infection among afebrile children. STUDY DESIGN: This retrospective multicenter cohort study used ACS NSQIP-P General and Targeted Appendectomy Participant Use Data Files from 2019-2023. Children ≤18 years undergoing appendectomy for complicated appendicitis with ≥1 intraoperative finding were included. Primary exposures were POD 3 or 4 fever and discharge antibiotic prescription. Outcomes were any surgical site infection and post-discharge surgical site infection within 30 days. Multivariable models adjusted for intraoperative findings, age, sex, race/ethnicity, operative approach, operative duration, preoperative white blood cell count, and ASA classification. RESULTS: Among 29,414 children, 3,944 (13.4%) developed surgical site infection. Fever occurred in 1,608 (5.5%); 758 (47.1%) developed surgical site infection versus 3,186/27,806 (11.46%) without fever (adjusted odds ratio 6.06, 95%CI 5.44 to 6.75). This association persisted across intraoperative finding strata, with no significant interaction. In 10,799 children discharged on POD 3 or 4 without fever or pre-discharge surgical site infection, 7,833 (72.5%) received discharge antibiotics. Post-discharge surgical site infection occurred in 453/7,833 (5.78%) with antibiotics versus 164/2,966 (5.53%) without antibiotics (adjusted odds ratio 1.03, 95%CI 0.86 to 1.24), unchanged in overlap-weighted sensitivity analysis. CONCLUSIONS: POD 3 or 4 fever was strongly associated with surgical site infection after pediatric complicated appendicitis. Among afebrile children discharged on POD 3 or 4, discharge antibiotics were not associated with lower post-discharge surgical site infection, supporting prospective evaluation of fever-guided antibiotic stewardship.