Postoperative Antibiotics, Outcomes, and Resource Use in Children With Gangrenous Appendicitis.

Importance:Gangrenous, suppurative, and exudative (GSE) findings have been associated with increased surgical site infection (SSI) risk and resource use in children with nonperforated appendicitis. Establishing the role for postoperative antibiotics may have important implications for infection prevention and antimicrobial stewardship. Objective:To compare SSI rates in children with nonperforated appendicitis with GSE findings who did and did not receive postoperative antibiotics. Design, Setting, and Participants:This was a retrospective cohort study using American College of Surgeons' National Surgical Quality Improvement Program (NSQIP)-Pediatric Appendectomy Targeted data from 16 hospitals participating in a regional research consortium. NSQIP data were augmented with operative report and antibiotic use data obtained through supplemental medical record review. Children with nonperforated appendicitis with GSE findings who underwent appendectomy between July 1, 2015, and June 30, 2020, were identified using previously validated intraoperative criteria. Data were analyzed from October 2022 to July 2023. Exposure:Continuation of antibiotics after appendectomy. Main Outcomes and Measures:Rate of 30-day postoperative SSI including both incisional and organ space infections. Complementary hospital and patient-level analyses were conducted to explore the association between postoperative antibiotic use and severity-adjusted outcomes. The hospital-level analysis explored the correlation between postoperative antibiotic use and observed to expected (O/E) SSI rate ratios after adjusting for differences in disease severity (presence of gangrene and postoperative length of stay) among hospital populations. In the patient-level analysis, propensity score matching was used to balance groups on disease severity, and outcomes were compared using mixed-effects logistic regression to adjust for hospital-level clustering. Results:A total of 958 children (mean [SD] age, 10.7 [3.7] years; 567 male [59.2%]) were included in the hospital-level analysis, of which 573 (59.8%) received postoperative antibiotics. No correlation was found between hospital-level SSI O/E ratios and postoperative antibiotic use when analyzed by either overall rate of use (hospital median, 53.6%; range, 31.6%-100%; Spearman ρ = -0.10; P = .71) or by postoperative antibiotic duration (hospital median, 1 day; range, 0-7 days; Spearman ρ = -0.07; P = .79). In the propensity-matched patient-level analysis including 404 patients, children who received postoperative antibiotics had similar rates of SSI compared with children who did not receive postoperative antibiotics (3 of 202 [1.5%] vs 4 of 202 [2.0%]; odds ratio, 0.75; 95% CI, 0.16-3.39; P = .70). Conclusions and Relevance:Use of postoperative antibiotics did not improve outcomes in children with nonperforated appendicitis with gangrenous, suppurative, or exudative findings.