Evaluation of antibiotic prophylaxis and other factors affecting the incidence of surgical site infection in appendectomy at a tertiary medical center in Lebanon. (c2003)

Abstract

Background: Appropriate antibiotic prophylaxis can reduce the incidence of surgical site infections (55I) in many procedures. Its role in acutely inflamed appendicitis remains controversial. Complicated appendicitis is frequently associated with superlative complications. Objectives: The objective is to evaluate the appropriateness of antibiotic prophylaxis in patients undergoing appendectomy at a tertiary care medical center; to assess the antibiotic choice, timing, and duration of administration; and to determine the impact and the value of intraoperative cultures on the selection of antibiotics. Material and Methods: The medical charts of patients with a positive pathology for acute, gangrenous or perforated appendicitis who underwent appendectomy between January l, 1999 and April 30, 2001 at American University of Beirut Medical Center (AUBMC), were retrospectively reviewed. Results: 99% of patients received antibiotic prophylaxis. 37% of cases received their preoperative prophylactic dose at 30-60 minutes before incision. 73% of patients who had acute appendicitis received prophylactic antibiotics for more than 24 hours. The most common regimen used preoperatively was amoxicillin/clavulanic acid while the triple regimen was the most frequently used postoperatively. 7%, of the study population, developed surgical site infection (SSI); all had emergency appendectomy, and 71% received inappropriate preoperative prophylaxis. Other contributing factors to the development of SSI were found to be the pathological state of the appendix, open surgical procedure, and pediatric age group. The mean added hospital stay for patients with SSI was 5 days per patient. 47% received oral antibiotics upon discharge. The most common organism isolated intraoperative was Escherichia coli in 70% of cases followed by Enterococci in 19% and Pseudomonas aeruginosa in 7.5%; no anaerobes were isolated. There was a 5% change in antibiotic regimen following the results of intraoperative cultures. Conclusion: Antibiotic prophylaxis is widely used in appendectomy with tendency towards long courses. It is an effective modality of reducing SS! if applied appropriately. Inappropriate prophylaxis, emergency surgery, open procedures, complicated appendicitis, and pediatric patients are major contributing factors to development of SSI. Intraoperative culture results did not significantly influence antibiotic therapy.