Antibiotic Stewardship in Acute Appendicitis

Authors:
Abby Gross, Ajita Prabhu, Benjamin T. Miller, Jeffrey Claridge, Sayf Said, Sofya Asfaw

Body of Abstract:
Background: Optimizing antibiotic stewardship in acute appendicitis is essential to improving care quality and combating antimicrobial resistance. We aimed to reduce the overutilization of broad-spectrum antibiotics for acute appendicitis within our hospital system through the implementation of an Emergency General Surgery (EGS) care pathway.

Methods: A task force comprised of residents and general surgery staff developed an evidence-based EGS care pathway for managing acute appendicitis in an iterative process. This pathway was implemented across six teaching hospitals within our health system through educational sessions, with periodic updates every three months based on outcomes review. This pathway was not implemented at an additional ten hospitals within our health system. Cases of acute appendicitis were identified via ICD-10 codes, covering 6 months before and after implementation (9/13/2023–9/13/2024).

The primary outcome was the use of guideline-compliant narrow-spectrum antibiotic regimens (Ceftriaxone, Ciprofloxacin, Levofloxacin, or Ertapenem with Flagyl) compared to broad-spectrum regimens (Piperacillin-tazobactam, Meropenem, Aztreonam/Flagyl, Cefepime/Flagyl). Secondary outcomes included postoperative antibiotic usage and duration, length of stay, and 30-day all-cause readmission.

Results: There were 972 cases evaluated during the study period, of which 460 were pre-implementation (44.2%) and 581 were post-implementation (55.8%). There was no significant difference in age, sex, Charlson Comorbidity Index, or complicated appendicitis rate before versus after implementing the care pathway (Table 1).

After care pathway implementation, the rate of narrow-spectrum antibiotics increased by 42.10% (p=0.035), while broad-spectrum antibiotic use decreased by 8.34% (p=0.012). The increase occurred at all six hospitals (Hospital A: 39.4% to 43.8%, Hospital B: 11.7% vs 31.6%, Hospital C: 18.7% to 19.5%, Hospital D: 15.1% to 18.2%, Hospital E: 16.7% to 20.0%, Hospital F: 12.2% to 13.7%). The appendectomy rate increased by 17.42% with the implementation of the care pathway (p<0.001). There was no statistically significant difference in the use of post-operative antibiotics (p=0.648) or duration of post-operative antibiotics (p=0.823). There was also no significant difference in length of stay (p=0.224), 30-day readmission rate (p=0.236), or percutaneous drain rate (p=1.000). A total of 1,876 cases of acute appendicitis occurred at the hospitals where the care pathway was not implemented during the same period. Among those hospitals, the rate of broad-spectrum antibiotic use increased from 55.29% to 61.50% (434 of 785 vs. 671 of 1,091; p=0.002), and post-operative antibiotics increased from 71.26% to 75.38% (434 of 611 vs. 686 of 911; p=0.075). Conclusion: Standardized care pathways across health systems promote antibiotic stewardship in acute appendicitis, reducing reliance on broad-spectrum antibiotics while maintaining clinical outcomes.