An audit of antimicrobial usage in perioperative period of adult patients undergoing appendectomy

We undertook a retrospective observational study at a central London teaching hospital to investigate antimicrobial prescribing in adult patients undergoing appendectomy between Jan2019 and Jun2019.

Results.

A total of 173 patients [median age 31year] were analysed; 7 and 167 had undergone an elective and urgent appendectomy respectively. 163/173 [94.2%] received antimicrobials peri-operatively. Compliance with local guidelines was 40.5%; a lack of aminoglycoside in combination with beta-lactam was common (58%). 126/173(72.8%) patients received antimicrobials on discharge, median 7.0 days total antimicrobials. Readmission rates within 30 days of surgery were 6.4% but unrelated to antimicrobial prescribing (p=0.8). Enterobacteriaceae was the most commonly identified pathogen (n=45), with high co-amoxiclav resistance reported (31%).

Conclusions

Combination co-amoxiclav plus aminoglycoside is advised peri-operatively for appendectomies yet adherence is poor. Despite local co-amoxiclav resistance, aminoglycosides are often omitted. The number of patients treated with post-op antimicrobials and the duration of therapy is greater than comparable published studies. Lack of standard definitions for complicated appendectomies makes it difficult to identify patients that do benefit from post-operative antimicrobials thus overprescribing occurs. Agreement on the optimum duration of treatment also is unclear and results in likely excessive prescribing.