The appropriateness of ceftriaxone and metronidazole as empirical therapy in managing complicated intra-abdominal infection—experience from Western Health, Australia

Abstract

PurposeThis study aims to assess the microbiological profile, antimicrobial susceptibility and adequacy of intravenous ceftriaxone and metronidazole as empirical therapy for surgical patients presenting with complicated intra-abdominal infection.MethodsThis retrospective audit reviews the microbiological profile and sensitivity of intra-abdominal cultures from adult patients with complicated intra-abdominal infection who presented to the emergency department at Western Health (Melbourne, Australia) between November 2013 and June 2017. Using the hospital’s database, an audit was completed using diagnosis related group (DRG) coded data. Ethics approval has been granted by the Western Health Human Research Ethics Committee. Results are stratified according to surgical conditions (appendicitis, cholecystitis, sigmoid diverticulitis and bowel perforation). The antimicrobial coverage of ceftriaxone and metronidazole is evaluated against these microbial profiles.ResultsA total of 1,412 patients were identified using DRG codes for intra-abdominal infection. All patients with microscopy and sensitivity results were included in the study. Patients without these results were excluded. 162 patients were evaluable. 180 microbiological cultures were performed through surgical intervention or radiologically guided aspiration of the intra-abdominal infection. Single or multiple pathogens were identified in 137 cultures. The most commonly identified pathogens were mixed anaerobes (12.6%), Escherichia coli (E. coli) (12.1%), mixed coliforms (11.6%) and Pseudomonas aeruginosa (7%). Other common pathogens (6% each) included Enterococcus faecalis, Streptococcus anginosus, Vancomycin-resistant Enterococci (VRE) and Extended Spectrum Beta-Lactamases (ESBL) producing E. coli. Organisms isolated in our study are consistent with existing literature. However, a significant proportion of antibiotic resistant organisms was identified in cases of perforated bowel and sigmoid diverticulitis. Broader spectrum antimicrobial therapy should therefore be considered in lieu of ceftriaxone and metronidazole in these cases. Ceftriaxone and metronidazole remain as appropriate empirical therapy for patients who presented with perforated appendicitis and cholecystitis.DiscussionThe empirical regime of ceftriaxone and metronidazole remains appropriate for intra-abdominal infection secondary to appendicitis and cholecystitis. In cases involving perforated small and large bowel, including complicated sigmoid diverticulitis, the judicious use of ceftriaxone and metronidazole is recommended.

Routine Intraoperative Bacterial Culture May Be Needed in Complicated Appendicitis

“…Current guidelines from SIS-IDSA and WSES recommend a several antibiotics regimen for community-acquired complicated appendicitis [ 3 - 5 ]. Among these regimens, the combination of ceftriaxone and metronidazole has been reported as appropriate in comparison with the past regimen, with a rate of IEAT reported at 4.1% (2 of 49) [ 14 , 15 ]. In this study, the rate of IEAT was 31.2% (54 of 173) using the same antibiotic regimen.…”

Antimicrobial Susceptibility of Microorganisms Isolated from Patients with Intraabdominal Infection in Korea: a Multicenter Study

“…Some studies have suggested that the isolation of Enterococcus in patients with IAIs results in treatment failure or increased mortality,293031 while others demonstrated no association with mortality 3233. Furthermore, some studies have shown equivalent therapeutic effects among empiric antibiotic regimens, regardless of the antimicrobial activity against enterococci 34353637. At present, prominent guidelines recommend empirical anti-enterococcal therapy for patients with nosocomial IAIs and severe community-acquired IAIs 1028…”

Effectiveness of integrated prophylactic antibiotics prescription in patients undergoing radiofrequency and microwave ablation of liver tumors: a retrospective cohort study

“…However, AP must be stopped within 24 hours of the procedure to prevent the emergence of resistant bacteria (15). Ceftriaxone and metronidazole were commonly used antibiotics, likely due to their indications extending to intra-abdominal infections (16).…”