O2087: Association Between Use of Postoperative Antibiotics and Outcomes in Non-perforated Appendicitis with Gangrene, Suppuration or Fibrinous Exudate: A Multi-center Propensity Matched Analyses

Background: Controversy exists regarding the benefit of postoperative antibiotics in children with non-perforated appendicitis who are found to have gangrene, suppuration or exudative findings (GSE findings). The goal of this analysis was to explore the association between use of postoperative antibiotics and surgical site infection (SSI) rates and resource utilization.

Methods: This was a multicenter cohort study of 15 children’s hospitals participating in a regional research consortium using data from NSQIP-Pediatric augmented with antibiotic utilization and operative report data obtained through supplemental chart review. Children with non-perforated appendicitis with any of the three GSE findings who underwent appendectomy from 7/2015 to 6/2020 were included. The presence of GSE findings (and absence of perforated disease) were established through a previously validated and standardized keyword-based audit of operative reports by consortium surgeons. The primary outcome was rate of 30-day postoperative SSI (incisional or organ space [OSI]), and secondary outcomes included postoperative imaging and revisits to the ED or inpatient setting. Logistic regression was used to compare outcomes between those who did and did not receive postoperative antibiotics (ABX+/ABX-) after propensity matching on demographic characteristics, intraoperative severity (presence/absence of gangrene as part of GSE findings), and clinical severity (postoperative length of stay [PLOS]).

Results: 781 patients with GSE findings met inclusion criteria with a median PLOS of 1 day (distribution: 0 days [4.9%], 1 day [54.9%], 2 days [40.3%]). 52.8% of all patients received postoperative antibiotics with a median treatment duration of 1 day (IQR: 0 to 4 days). Postoperative antibiotic utilization varied significantly across hospitals, ranging from 20 to 100% (p < 0.001, figure); use of oral antibiotics after discharge ranged from 0-50% (p < 0.001), and the mean postoperative treatment duration ranged from 0.4-4.9 days (p < 0.001). The overall rate of SSI was 1.3% and was similar between patients who did and did not receive postoperative antibiotics (1.0% vs. 1.6%, p=0.42). Following propensity matching, no differences in patient characteristics or disease severity were found between groups. In the matched sample of 382 patients, adjusted outcomes were similar between groups for OSI (ABX+: 0.5% vs. ABX-: 1.6%; p=0.62) postoperative imaging (ABX+: 4.3% vs. ABX-: 2.3%; p=0.28), and hospital revisits (ABX+: 6.8% vs. ABX-: 4.7%, p=0.38).

Conclusion: Substantial variation exists in the use of postoperative antibiotics in children with non-perforated appendicitis with GSE findings. SSI’s were uncommon with or without postoperative antibiotics and use of antibiotics did not improve outcomes or reduce postoperative imaging or revisits. The results of this analysis suggest postoperative antibiotics may be not be necessary in children with nonperforated appendicitis with GSE findings.