Wound infection rates following preoperative versus intraoperative commencement of antibiotic prophylaxis

Area of Science:

• Infectious Diseases
• Surgical Infections
• Microbiology

Background:

• Surgical site infections (SSIs) are a significant cause of morbidity and mortality.
• Antibiotic prophylaxis is a common strategy to prevent SSIs.
• The optimal timing for initiating antibiotic prophylaxis remains a subject of investigation.

Purpose of the Study:

• To evaluate the efficacy of antibiotic prophylaxis in a guinea pig model of surgical wound infection.
• To determine if the timing of antibiotic administration (pre-contamination vs. at-contamination) affects infection rates.

Main Methods:

• A randomized blind study was conducted using a guinea pig model.
• Surgical wounds were contaminated with Escherichia coli and Bacteroides fragilis.
• Antibiotic prophylaxis (gentamicin plus clindamycin) was administered either one hour before or at the time of contamination.
• Infection rates, rectal temperature, and bacterial recovery were assessed.

Main Results:

• Antibiotic prophylaxis significantly reduced the wound sepsis rate from 82% in the control group to 19% in the treated groups (p < 0.001).
• The timing of antibiotic prophylaxis initiation did not significantly influence wound sepsis rates.
• Postoperative rectal temperature and bacterial recovery from wound infections were also not affected by the timing of prophylaxis.

Conclusions:

• Antibiotic prophylaxis with gentamicin and clindamycin is highly effective in preventing surgical wound infections.
• The timing of antibiotic prophylaxis initiation, whether before or at the time of contamination, does not impact its efficacy in this model.
• These findings support the use of antibiotic prophylaxis in preventing SSIs, with flexibility in administration timing.