Longer Durations of Intravenous Antibiotics are Not Protective for Pediatric Complicated Appendicitis Treated According to a Pragmatic Standardized Protocol

Authors:
Jeannette Joly, Krysta Sutyak, Erin Morris, Terry Fisher, Erich Grethel, Monica Lopez, KuoJen Tsao, Kevin Lally

Body of Abstract:
Background: The Pediatric Surgery Quality Collaborative (PSQC) conducted a pilot study wherein 21 hospitals adopted an evidence-based, short-course antibiotic protocol (4+/-1 total days) for postoperative pediatric complicated appendicitis. The pragmatic protocol allowed intravenous (IV) antibiotic duration to be at the discretion of the prescriber. This study aims to evaluate the impact of IV antibiotic duration on patient outcomes specifically in those treated with short-course antibiotics.

Methods: A retrospective review was conducted of PSQC protocol-adopting hospitals (07/2023-06/2025). De-identified hospital data were obtained in quartiles from the National Surgical Quality Improvement Program-Pediatric procedure-targeted and custom variable fields. Pediatric complicated appendicitis patients were included if they received postoperative short-course antibiotics: a total of 5 days or fewer. Univariate and multi-level multivariate analyses, and Spearman’s correlation coefficient (ρ) were utilized.

Results: Across 21 adopter hospitals, 1421 patients were treated with short-course antibiotics. Patients were median age 10.2 years (IQR: 7.3-13.3) and 58% male. Overall, the median total antibiotic duration was 4.0 days (IQR: 3.0-5.0), IV antibiotic duration was 3.0 days (IQR: 2.0-4.0), and hospital length of stay (LOS) was 3.0 days (IQR: 2.0-4.0). Rate of organ space surgical site infection (OS-SSI) was 5.6% overall, but varied by duration of IV antibiotics: 2.5% for 0 days, 1.5% for 1 day, 2.3% for 2 days, 5.7% for 3 days, 7.1% for 4 days, and 9.6% for 5 days. After controlling for gender, body mass index, sepsis grade, anesthesia class, procedure duration, and intraoperative visible findings, each additional day of IV antibiotics was associated with an absolute increase in predicted probability of developing an OS-SSI by 1.9% (95% CI: 0.7-3.2; p<0.01) (FIGURE), of having at least one emergency department (ED) visit by 3.7% (95% CI: 2.0-5.4; p<0.01), and of having at least one hospital readmission by 2.2% (95% CI: 0.9-3.5; p<0.01). A strong, positive correlation was detected between total IV antibiotic days and hospital LOS (ρ: 0.73; p<0.01), with median hospital LOS of 1 day (IQR: 1-3) for those with 0 IV antibiotic days, up to 5 days (IQR: 5-6) for those 5 days of IV antibiotics. Conclusion: Durations of IV antibiotics are highly variable in patients who receive short-course antibiotics according to a standardized pragmatic protocol, with longer durations not necessarily protective against subsequent SSIs, ED visits, or readmissions. This suggests that certain patients may be more likely to develop infection and/or have increased healthcare utilization regardless of IV antibiotic durations. Additionally, since IV antibiotic duration is directly correlated with hospital LOS, it may follow that fewer IV antibiotic days leads to shorten hospital stays without specifically increasing infection risk or healthcare utilization.