Skip to main navigation menu Skip to main content Skip to site footer

Original article

Vol. 152 No. 3536 (2022)

Evidence-based optimisation of empirical antibiotic regimens in paediatric complicated appendicitis: a retrospective study of 94 patients

  • Filippo Gerber
  • Jean-Marc Joseph 
  • Pierre-Alex Crisinel 
  • Véronique Andrey
Cite this as:
Swiss Med Wkly. 2022;152:w30222


BACKGROUND: Acute appendicitis is the most frequent surgical emergency in the paediatric population. Complicated appendicitis accounts for 30% of cases and is inextricably linked to postoperative infectious complications. A study at our institution showed that amoxicillin-clavulanate resistant Escherichia coli  in complicated appendicitis was significantly linked to postoperative infectious complications. These findings led to a change in the empirical antibiotic protocol (amoxicillin-clavulanate changed to ceftriaxone + metronidazole as of 2017), intending to reduce postoperative infectious complications in complicated appendicitis in our institution.

AIM OF THE STUDY: This study aimed to analyse the microbiology and resistance profiles of pathogens of complicated appendicitis at our institution since implementing the new antibiotic protocol and the postoperative infectious complications rate.

METHODS: We designed a retrospective comparative cohort study. During the defined study period (01 January 2017 to 31 July 2020), medical records were analysed for cases of acute appendicitis, complicated appendicitis and postoperative infectious complications, retaining only those who fulfilled inclusion criteria. Postoperative outcomes, microbiology and antibiotic resistance of peritoneal swabs were analysed.

RESULTS: During the study period, 95 patients presented with a complicated appendicitis, and 11 (12%) developed postoperative infectious complications. The most frequent pathogens found in complicated appendicitis were E. coli (66%), Streptococcus anginosus (45%), and Bacteroides fragilis (22%). Pseudomonas aeruginosa was present in 17% of complicated appendicitis. Pathogens involved in postoperative infectious complications mirrored the distribution found in complicated appendicitis without postoperative infectious complications. Antibiotic susceptibility analysis showed that 10 (15%) of E. coli strains were resistant to amoxicillin-clavulanate but sensitive to ceftriaxone + metronidazole, with only one strain responsible for causing a postoperative infectious complication. Six additional strains of E. coli (9%) were resistant to amoxicillin-clavulanate and our empirical antibiotic regimen but were not associated with an increase in postoperative infectious complications. Compared with our previous study, there was a decrease in postoperative infectious complications from 16% to 12%. Postoperative infectious complications caused by amoxicillin-clavulanate-resistant E. coli decreased from 28% to 9%.

CONCLUSION: This retrospective study demonstrated a decrease in the rate of postoperative infectious complications due to amoxicillin-clavulanate-resistant E. coli in complicated appendicitis. These findings accentuate the need to implement evidence-based treatment protocols based on local microbiology profiles and resistance rates to optimise post-operative antibiotics in complicated appendicitis.


  1. Lee SL, Islam S, Cassidy LD, Abdullah F, Arca MJ ; 2010 American Pediatric Surgical Association Outcomes and Clinical Trials Committee. Antibiotics and appendicitis in the pediatric population: an American Pediatric Surgical Association Outcomes and Clinical Trials Committee systematic review. J Pediatr Surg. 2010 Nov;45(11):2181–5.
  2. Salö M, Marungruang N, Roth B, Sundberg T, Stenström P, Arnbjörnsson E, et al. Evaluation of the microbiome in children’s appendicitis. Int J Colorectal Dis. 2017 Jan;32(1):19–28.
  3. Obrist NM, Tschuor C, Breitenstein S, Vuille-Dit-Bille RN, Soll C. Appendectomy in Switzerland: how is it done? Updates Surg. 2019 Jun;71(2):375–80.
  4. Becker P, Fichtner-Feigl S, Schilling D. Clinical Management of Appendicitis. Visc Med. 2018 Dec;34(6):453–8.
  5. McGillen PK, Drake FT, Vallejo A, Brahmbhatt TS, Sanchez SE. Retrospective Analysis of Post-Operative Antibiotics in Complicated Appendicitis. Surg Infect (Larchmt). 2019 Jul;20(5):359–66.
  6. Svetanoff WJ, Talukdar N, Dekonenko C, Dorman RM, Osuchukwu O, Fraser JD, et al. Intra-abdominal Abscess After Appendectomy-Are Drains Necessary in All Patients? J Surg Res. 2020 Oct;254:384–9.
  7. Chen C, Botelho C, Cooper A, Hibberd P, Parsons SK. Current practice patterns in the treatment of perforated appendicitis in children. J Am Coll Surg. 2003 Feb;196(2):212–21.
  8. Pham XD, Sullins VF, Kim DY, Range B, Kaji AH, de Virgilio CM, et al. Factors predictive of complicated appendicitis in children. J Surg Res. 2016 Nov;206(1):62–6.
  9. Frazee R, Abernathy S, Davis M, Isbell T, Regner J, Smith R. Fast track pathway for perforated appendicitis. Am J Surg. 2017 Apr;213(4):739–41.
  10. Bhangu A, Søreide K, Di Saverio S, Assarsson JH, Drake FT. Acute appendicitis: modern understanding of pathogenesis, diagnosis, and management. Lancet. 2015 Sep;386(10000):1278–87.
  11. Chen CY, Chen YC, Pu HN, Tsai CH, Chen WT, Lin CH. Bacteriology of acute appendicitis and its implication for the use of prophylactic antibiotics. Surg Infect (Larchmt). 2012 Dec;13(6):383–90.
  12. García-Marín A, Pérez-López M, Martínez-Guerrero E, Rodríguez-Cazalla L, Compañ-Rosique A. Microbiologic Analysis of Complicated and Uncomplicated Acute Appendicitis. Surg Infect (Larchmt). 2018 Jan;19(1):83–6.
  13. Fallon SC, Hassan SF, Larimer EL, Rodriguez JR, Brandt ML, Wesson DE, et al. Modification of an evidence-based protocol for advanced appendicitis in children. J Surg Res. 2013 Nov;185(1):273–7.
  14. Ong CP, Chan TK, Chui CH, Jacobsen AS. Antibiotics and postoperative abscesses in complicated appendicitis: is there any association? Singapore Med J. 2008 Aug;49(8):615–8.
  15. Obinwa O, Casidy M, Flynn J. The microbiology of bacterial peritonitis due to appendicitis in children. Ir J Med Sci 1971 -. 2014;183(4):585‑91. DOI:
  16. Andrey V, Crisinel PA, Prod’hom G, Croxatto A, Joseph JM. Impact of co-amoxicillin-resistant Escherichia coli and Pseudomonas aeruginosa on the rate of infectious complications in paediatric complicated appendicitis. Swiss Med Wkly. 2019 Apr;149:w20055.
  17. Loux TJ, Falk GA, Burnweit CA, Ramos C, Knight C, Malvezzi L. Early transition to oral antibiotics for treatment of perforated appendicitis in pediatric patients: confirmation of the safety and efficacy of a growing national trend. J Pediatr Surg. 2016 Jun;51(6):903–7.
  18. Bonadio W, Rebillot K, Ukwuoma O, Saracino C, Iskhakov A. Management of Pediatric Perforated Appendicitis: Comparing Outcomes Using Early Appendectomy Versus Solely Medical Management. Pediatr Infect Dis J. 2017 Oct;36(10):937–41.
  19. Shang Q, Geng Q, Zhang X, Guo C. The efficacy of combined therapy with metronidazole and broad-spectrum antibiotics on postoperative outcomes for pediatric patients with perforated appendicitis. Medicine (Baltimore). 2017 Nov;96(47):e8849.
  20. Dreznik Y, Feigin E, Samuk I, Kravarusic D, Baazov A, Levy I, et al. Dual versus Triple Antibiotics Regimen in Children with Perforated Acute Appendicitis. Eur J Pediatr Surg. 2018 Dec;28(6):491–4.
  21. St Peter SD, Tsao K, Spilde TL, Holcomb GW 3rd, Sharp SW, Murphy JP, et al. Single daily dosing ceftriaxone and metronidazole vs standard triple antibiotic regimen for perforated appendicitis in children: a prospective randomized trial. J Pediatr Surg. 2008 Jun;43(6):981–5.
  22. Pogorelić Z, Silov N, Jukić M, Elezović Baloević S, Poklepović Peričić T, Jerončić A. Ertapenem Monotherapy versus Gentamicin Plus Metronidazole for Perforated Appendicitis in Pediatric Patients. Surg Infect (Larchmt). 2019 Dec;20(8):625–30.
  23. Hurst AL, Olson D, Somme S, Child J, Pyle L, Ranade D, et al. Once-Daily Ceftriaxone Plus Metronidazole Versus Ertapenem and/or Cefoxitin for Pediatric Appendicitis. J Pediatr Infect Dis Soc. 2015;piv082. DOI:
  24. Goldin AB, Sawin RS, Garrison MM, Zerr DM, Christakis DA. Aminoglycoside-based triple-antibiotic therapy versus monotherapy for children with ruptured appendicitis. Pediatrics. 2007 May;119(5):905–11.
  25. Song DW, Park BK, Suh SW, Lee SE, Kim JW, Park JM, et al. Bacterial culture and antibiotic susceptibility in patients with acute appendicitis. Int J Colorectal Dis. 2018 Apr;33(4):441–7.
  26. Chan KW, Lee KH, Mou JW, Cheung ST, Sihoe JD, Tam YH. Evidence-based adjustment of antibiotic in pediatric complicated appendicitis in the era of antibiotic resistance. Pediatr Surg Int. 2010 Feb;26(2):157–60.
  27. Coccolini F, D’Amico G, Sartelli M, Catena F, Montori G, Ceresoli M, et al. Antibiotic resistance evaluation and clinical analysis of acute appendicitis; report of 1431 consecutive worldwide patients: A cohort study. Int J Surg. 2016 Feb;26:6–11.
  28. Solomkin JS, Mazuski JE, Bradley JS, Rodvold KA, Goldstein EJ, Baron EJ, et al. Diagnosis and management of complicated intra-abdominal infection in adults and children: guidelines by the Surgical Infection Society and the Infectious Diseases Society of America. Clin Infect Dis. 2010 Jan;50(2):133–64.
  29. Reinisch A, Malkomes P, Habbe N, Bechstein WO, Liese J. Bad bacteria in acute appendicitis: rare but relevant. Int J Colorectal Dis. 2017 Sep;32(9):1303–11.
  30. Dahlberg M, Almström M, Wester T, Svensson JF. Intraoperative cultures during appendectomy in children are poor predictors of pathogens and resistance patterns in cultures from postoperative abscesses. Pediatr Surg Int. 2019 Mar;35(3):341–6.
  31. Taleb M, Nardi N, Arnaud A, Costet N, Donnio PY, Engrand C, et al. Simplification of first-line antibacterial regimen for complicated appendicitis in children is associated with better adherence to guidelines and reduced use of antibiotics. Int J Antimicrob Agents. 2018 Aug;52(2):293–6.
  32. Turel O, Mirapoglu SL, Yuksel M, Ceylan A, Gultepe BS. Perforated appendicitis in children: antimicrobial susceptibility and antimicrobial stewardship. J Glob Antimicrob Resist. 2019 Mar;16:159–61.
  33. Montuori M, Santurro L, Gianotti L, Fattori L. Uselessness of microbiological samples in acute appendicitis with frank pus: to collect or not to collect? Eur J Trauma Emerg Surg. 2020 Aug;46(4):835–9.
  34. Subramanian T, Jerome E, Jones I, Jester I. Streptococcus anginosus is associated with postoperative intraabdominal collections in appendicitis. J Pediatr Surg. 2018 Feb;53(2):237–40.
  35. Bassetti M, Peghin M, Mesini A, Castagnola E. Optimal Management of Complicated Infections in the Pediatric Patient: The Role and Utility of Ceftazidime/Avibactam. Infect Drug Resist. 2020 Jun;13:1763–73.
  36. Fraser JD, Aguayo P, Sharp SW, Snyder CL, Holcomb GW 3rd, Ostlie DJ, et al. Physiologic predictors of postoperative abscess in children with perforated appendicitis: subset analysis from a prospective randomized trial. Surgery. 2010 May;147(5):729–32.
  37. Frongia G, Mehrabi A, Ziebell L, Schenk JP, Günther P. Predicting Postoperative Complications After Pediatric Perforated Appendicitis. J Invest Surg. 2016 Aug;29(4):185–94.
  38. Emil S, Elkady S, Shbat L, Youssef F, Baird R, Laberge JM, et al. Determinants of postoperative abscess occurrence and percutaneous drainage in children with perforated appendicitis. Pediatr Surg Int. 2014 Dec;30(12):1265–71.
  39. Tartaglia D, Fatucchi LM, Mazzoni A, Miccoli M, Piccini L, Pucciarelli M, et al. Risk factors for intra-abdominal abscess following laparoscopic appendectomy for acute appendicitis: a retrospective cohort study on 2076 patients. Updat Surg. 2020; DOI:
  40. Di Saverio S, Podda M, De Simone B, Ceresoli M, Augustin G, Gori A, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020 Apr;15(1):27.
  41. Yousef Y, Youssef F, Homsy M, Dinh T, Pandya K, Stagg H, et al. Standardization of care for pediatric perforated appendicitis improves outcomes. J Pediatr Surg. 2017 Dec;52(12):1916–20.
  42. Lee JY, Ally S, Kelly B, Kays D, Thames L. Once Daily Dosing of Ceftriaxone and Metronidazole in Children With Perforated Appendicitis. J Pediatr Pharmacol Ther. 2016 Mar-Apr;21(2):140–5.
  43. Hamdy RF, Handy LK, Spyridakis E, Dona D, Bryan M, Collins JL, et al. Comparative Effectiveness of Ceftriaxone plus Metronidazole versus Anti-Pseudomonal Antibiotics for Perforated Appendicitis in Children. Surg Infect (Larchmt). 2019 Jul;20(5):399–405.
  44. Guillet-Caruba C, Cheikhelard A, Guillet M, Bille E, Descamps P, Yin L, et al. Bacteriologic epidemiology and empirical treatment of pediatric complicated appendicitis. Diagn Microbiol Infect Dis. 2011 Apr;69(4):376–81.
  45. Lob SH, Badal RE, Hackel MA, Sahm DF. Epidemiology and Antimicrobial Susceptibility of Gram-Negative Pathogens Causing Intra-abdominal Infections in Pediatric Patients in Europe—SMART 2011–2014. J Pediatric Infect Dis Soc. 2014;2016:piv109.