Presenter Status
Fellow
Abstract Type
Research
Primary Mentor
Shawn St. Peter
Start Date
15-5-2025 12:15 PM
End Date
15-5-2025 12:30 PM
Presentation Type
Oral Presentation
Description
Background/Purpose
Perforated appendicitis is associated with elevated risk of post-operative intra-abdominal abscess (PIAA) formation. Small PIAAs can be successfully treated without drainage, while larger ones warrant Interventional Radiology drainage. Routine culture of drained abscesses occurs at most institutions, with some prior studies showing resistance rates of 40-50%, prompting change of post-drainage antibiotics. The purpose of our study is to evaluate if culture results impact the antimicrobial therapy chosen for patients with PIAA, with our hypothesis being that routine culture does not have a significant impact on patient outcomes.
Methods
Patients < 18 years of age who were treated for perforated appendicitis at a standalone tertiary children’s hospital from 2011 to 2024 were retrospectively evaluated for abscess formation and extracted those who underwent drainage procedures with abscess cultures to assess the need for antibiotic adjustments from the standard of care based on culture results.
Results
A total of 1736 patients treated for perforated appendicitis were identified, of which 181 developed a PIAA (10.4%). Of those, 111 underwent drainage with culture. 14 of these patients (12.6%) had a change in antibiotics based on culture results. Six (6) changes were due to Pseudomonas, 4 due to Candida species, 2 due to Enterococcus, and 1 from resistant E. Coli and Eggerthella each. Those who underwent antibiotic changes had a prolonged total treatment course, with median therapy days of 27.7 versus 23.5 in those without change (p-value 0.02).
Conclusions
We found a lower than previously reported rate of antimicrobial resistance to standard therapy. A majority of abscesses resolved with just standard therapy and changes to antibiotic therapy were strictly driven by cultures and not necessarily clinical deterioration. Given these findings, routine cultures may not be necessary in the treatment of PIAA.
The Impact of Cultures on Treating Abscesses Associated with Appendicitis
Background/Purpose
Perforated appendicitis is associated with elevated risk of post-operative intra-abdominal abscess (PIAA) formation. Small PIAAs can be successfully treated without drainage, while larger ones warrant Interventional Radiology drainage. Routine culture of drained abscesses occurs at most institutions, with some prior studies showing resistance rates of 40-50%, prompting change of post-drainage antibiotics. The purpose of our study is to evaluate if culture results impact the antimicrobial therapy chosen for patients with PIAA, with our hypothesis being that routine culture does not have a significant impact on patient outcomes.
Methods
Patients < 18 years of age who were treated for perforated appendicitis at a standalone tertiary children’s hospital from 2011 to 2024 were retrospectively evaluated for abscess formation and extracted those who underwent drainage procedures with abscess cultures to assess the need for antibiotic adjustments from the standard of care based on culture results.
Results
A total of 1736 patients treated for perforated appendicitis were identified, of which 181 developed a PIAA (10.4%). Of those, 111 underwent drainage with culture. 14 of these patients (12.6%) had a change in antibiotics based on culture results. Six (6) changes were due to Pseudomonas, 4 due to Candida species, 2 due to Enterococcus, and 1 from resistant E. Coli and Eggerthella each. Those who underwent antibiotic changes had a prolonged total treatment course, with median therapy days of 27.7 versus 23.5 in those without change (p-value 0.02).
Conclusions
We found a lower than previously reported rate of antimicrobial resistance to standard therapy. A majority of abscesses resolved with just standard therapy and changes to antibiotic therapy were strictly driven by cultures and not necessarily clinical deterioration. Given these findings, routine cultures may not be necessary in the treatment of PIAA.
