531 - Standardizing Preoperative Antibiotics for Pediatric Appendicitis to Improve Stewardship and Outcomes

Publication Number: 2516.531

Michael A. Gardiner, University of California, San Diego School of Medicine, San Diego, CA, United States; Edmund A.. Milder, Rady Children's Hospital San Diego, San Diego, CA, United States; Benjamin A. keller, Rady Children's Hospital San Diego, San Diego, CA, United States; Alice Pong, University of California, San Diego School of Medicine, San Diego, CA, United States; Amy Bryl, University of California, San Diego and Rady Children’s Hospital San Diego, San Diego, CA, United States; Mario Bialostozky, Rady Children's Health, San Diego, CA, United States; Paige Anderson, Rady Children's Hospital San Diego, San Diego, CA, United States; Yvette Wang, Rady Children's Hospital San Diego, San Diego, CA, United States

Background: Acute appendicitis is the most common pediatric surgical emergency, with ~70,000 U.S. cases annually. Despite this, perioperative antibiotic regimens remain inconsistent across children's hospitals. Before 2024, our institution used cefoxitin or meropenem depending on perceived perforation status. To align with evidence showing comparable or improved outcomes using narrow-spectrum regimens and to meet institutional stewardship goals, we implemented a standardized perioperative antibiotic protocol to reduce broad-spectrum antipseudomonal use in ED patients undergoing appendectomy for acute appendicitis.

Objective: To Increase use of recommended first-line antibiotics-intravenous ceftriaxone and metronidazole (CRO-MTZ)-for all ED patients undergoing appendectomy for acute appendicitis from 0% to 75% within eight months.

Design/Methods: This single-center quality improvement initiative used a predictive project management model to guide planning and implementation. Interventions included electronic order set updates, revision of the institutional Appendicitis Pathway, and multidisciplinary education (ED, pediatric surgery, anesthesia, nursing, pharmacy) with a defined rollout date (Figure 1). The primary process measure was adherence to CRO-MTZ. Additional process measures were antipseudomonal antibiotic use and ED order set utilization. Balancing measures included hospital length of stay (LOS) and postoperative complication within 90 days (abscess drainage procedure or surgical site infection meeting National Healthcare Safety Network definition). Baseline data covered the 12 months preceding rollout. Statistical process control methods monitored change over time.

Results: Average adherence to CRO-MTZ increased from 0% to 87% with ED order-set utilization increasing from 44% to 69%. Preoperative antipseudomonal antibiotic use decreased from 19% to 6%. The rate of postoperative complications decreased from 6.1% to 0.9%. Mean hospital LOS decreased from 59.8 hours to 49.9 hours.

Conclusion(s): Standardizing perioperative antibiotics for pediatric acute appendicitis markedly improved adherence to recommended therapy and reduced broad-spectrum antipseudomonal antibiotic use, without increasing postoperative complications or hospital length of stay. Predictive, multidisciplinary planning enabled smooth implementation and sustained adherence for 12 months without iterative PDSA cycles.

Figure 1: Key Driver Diagram
Key driver diagram displaying the aims, drivers, and interventions utilized to increase use of recommended first-line antibiotics (ceftriaxone + metronidazole) for pediatric emergency department patients undergoing appendectomy.

Figure 2: Use of Recommended Preoperative Antibiotics
Statistical process control chart demonstrating adherence to the recommended perioperative antibiotic regimen (ceftriaxone + metronidazole) among pediatric appendectomy patients. Following project rollout, adherence increased from 0% to 87%, exceeding the 75% target and sustaining improvement over 12 months.

Figure 3: Postoperative Complications Within 90 Days
Statistical process control chart showing the composite rate of postoperative complications-defined as any surgical site infection meeting NHSN criteria or need for abscess drainage within 90 days of appendectomy. Following implementation of the standardized antibiotic protocol, complication rates decreased from 6.1% to 0.9% and remained low over 12 months.