1932. Microbiology, Antibiotic Choice, and Pre-op Factors: Appendicitis Outcomes and Antibiotic Stewardship
Session: Poster Abstract Session: Antibiotic Stewardship: Pediatrics
Saturday, October 29, 2016
Room: Poster Hall
  • IDweek Pediatric Appendicitis and Stewardship poster HZ.pdf (506.6 kB)
  • Background: Appendicitis is the most common pediatric surgical emergency and is a common reason for inpatient pediatric antibiotic use. Understanding pathogen prevalence and other factors which may play a role in severity or complications, may aid in appropriate antibiotic (abx) choice and in providing optimal and safe care.

    Methods: We performed a retrospective chart review of complicated appendicitis (CA) patients with or without adverse outcomes (including but not limited to post op abscess, sepsis, readmissions) admitted 2013-2015 to Stony Brook Children’s Hospital. Since 2013, all appendicitis patients have had peritoneal cultures and followed a standardized antibiotic protocol; it recommended IV piperacillin-tazobactam (P/T) for pre-op abx if concern for sepsis, WBC count >20, or perforation on imaging; and for post-op abx if met criteria for CA based on operative findings; others received IV cefoxitin. Data was analyzed by chi-square as categorical variables in SPSS.

    Results: 79 subjects with CA were analyzed. 24/79 (30%) had adverse outcomes; the most common was abscess formation (42%). Compliance with the pre-op antibiotic protocol was 63%; post-op protocol was 86%. Abnormal BMI (LR 8.2, p=.005), initial band count >10% (LR 4.2, p=.03), no abdominal pain on presentation (LR 10, p=.002), and culture positivity (LR 7.9, p=.023) were all associated with adverse outcomes. No association was seen with age/sex/ethnicity, symptom days, WBC/neutrophil count, and perforation on imaging, appendix pathology or type or number of bacteria isolated. 15% of cultures had no growth. The most common pathogen isolated was E. coli (43% ampicillin resistant, 7% ampicillin-sulbactam resistant, 2% P/T resistant, none 3rd-gen. cephalosporin resistant). Pseudomonas was isolated in only 8% of cultures. No association was seen with outcome & antibiotic susceptibility; only 1 organism was resistant to P/T.

    Conclusion: Identifying key factors may help risk-stratify children with CA and allow for earlier optimal surgical/antibiotic management. Resistance to protocol antibiotics did not correlate with poor outcomes though overall culture positivity did, suggesting intra-op cultures can be generally useful but further stewardship interventions is possible.

    Hina Zaidi, MD, Department of Pediatrics Infectious Diseases, Stony Brook Children's Hospital, Stony Brook, NY, Catherine Messina, PhD, Department of Family, Population, and Preventive Medicine, Stony Brook University, Stony Brook, NY and Saul Hymes, MD, Department of Pediatrics, Stony Brook Children's Hospital, Stony Brook, NY


    H. Zaidi, None

    C. Messina, None

    S. Hymes, None

    Findings in the abstracts are embargoed until 12:01 a.m. CDT, Wednesday Oct. 26th with the exception of research findings presented at the IDWeek press conferences.