Postoperative Antibiotics for Complicated Appendicitis in Children: Piperacillin/Tazobactam Versus Ceftriaxone with Metronidazole

Introduction: Recent studies are discordant regarding postoperative use of piperacillin/tazobactam (PT) versus ceftriaxone/metronidazole (CM) for pediatric complicated appendicitis. Some argue that the broader spectrum PT decreases intraabdominal abscess formation; however, antibiotic stewardship, and once-a-day dosing favor CM. We aim to compare outcomes of postoperative antibiotic utilization using a large administrative database. Methods: We queried the Pediatric Health Information System for patients 2–18 years old who underwent laparoscopic appendectomy for complicated appendicitis between 2016 and 2021. Patients were grouped into PT, CM, or other using the first postoperative day antibiotics. Adverse events and antibiotic use trends were evaluated. Results: We included 29,015 children from 45 hospitals. CM was used in 51.9% and 31.3% received PT. Wide variation was seen among hospitals with PT use decreasing over the years. Overall rate of abscess was 9.2%. On multivariable regression, PT was associated with higher risk for abscess formation (RR 1.35, 99% CI 1.04–1.75) and readmission (RR 1.38, 99% CI 1.13–1.68) compared to the CM group. However, following adjustment for hospitals with high CM prevalence, these associations were no longer significant. Conclusion: Postoperative use of PT for complicated appendicitis is associated with higher rates of readmissions and intraabdominal abscess when compared to CM. However, this effect is mitigated when adjusting for common practice patterns. Level of Evidence: Level III. Study Type: Retrospective Comparative Study.