Reducing Surgical Site Infection and Sepsis after Hysterectomy: Cefazolin Compared with Cefazolin Plus Metronidazole

Study Objective

To evaluate if cefazolin plus metronidazole before a hysterectomy will be more effective in prevention of surgical site infection (SSI) and sepsis compared to the existing recommendation of preoperative cefazolin alone.

Design

Retrospective chart review.

Setting

Henry Ford Health System (HFHS).

Patients or Participants

Data was collected for 1485 adult patients who received hysterectomies within HFHS for benign and malignant conditions. The control group (group 1) was obtained via retrospective chart review to include patients who had a hysterectomy between January 2019 and June 2020 and received cefazolin alone as antibiotic prophylaxis. The treatment group (group 2) included patients who had a hysterectomy between July 2020 and January 2022 and received preoperative cefazolin plus metronidazole.

Interventions

Addition of metronidazole to cefazolin as antibiotic prophylaxis prior to hysterectomy.

Measurements and Main Results

Of the 1485 patients, 789 (53.1%) were given cefazolin alone and 696 (46.9% were given cefazolin plus metronidazole. There was a total of six (0.4%) patients who experienced sepsis and 37 (2.5%) who had a site infection across both groups. There was a decrease in both sepsis and SSI in group 2, however it did not reach statistical significance. The model for the risk of sepsis is adjusted for obesity (BMI ≥30), procedure length >2 hours, and gynecologic cancer. We found that there were no significant differences in the risk of sepsis between the two treatment groups after adjusting for these risk factors (p=0.736). The model for the risk of site infection is adjusted for diabetes, obesity, smoking status, procedure length, and gynecologic cancer. We found that there were no significant differences in the risk of site of infection between the two treatment groups (p=0.451).

Conclusion

The addition of metronidazole to the standard antibiotic prophylaxis regimen for hysterectomy did not significantly reduce the rate of surgical site infections or sepsis within our health system.