Effect of Augmented Antimicrobial Prophylaxis and Rectal Swab Culture-guided Targeted Prophylaxis on the Risk of Sepsis Following Transrectal Prostate Biopsy

Background: Sepsis is a severe complication following transrectal ultrasound-guided prostate biopsy (TRUSPBx). Ciprofloxacin is commonly used for prophylaxis; however, there is an increasing incidence of resistant enteric organisms worldwide.

Objective: To investigate the effect of a targeted prophylactic antimicrobial regimen based on rectal swab cultures in reducing the rate of sepsis.

Design, setting, and participants: A total of 1012 patients were included. Group A (609 patients) received an empirical prophylactic antimicrobial regimen of gentamicin, metronidazole, and ciprofloxacin. Targeted antimicrobial prophylaxis was introduced due to significant ciprofloxacin and gentamicin resistance in patients admitted with sepsis following TRUSPBx. The remaining 403 patients (Group B) had rectal swab cultures performed prior to biopsy. Patients with organisms resistant to ciprofloxacin or gentamicin received a targeted prophylaxis regimen of fosfomycin, amikacin, and metronidazole.

Outcome measurements and statistical analysis: We retrospectively collected and analysed data on sepsis and bacteraemia for all patients as well as data on rectal swab culture, recent foreign travel, and recent antibiotic use for patients in Group B.

Results and limitations: In group A, 12 (2.0%) patients developed sepsis following TRUSPBx, while in group B, 9 (2.2%) patients developed sepsis despite targeted prophylaxis (p=0.82). Patients with ciprofloxacin-resistant rectal flora had a significantly higher rate of sepsis (9.1% vs 1.1%; p=0.003). There was a reduction in patients admitted with bacteraemia and severe sepsis between group A (1.2%) and group B (0.3%) which did not reach statistical significance (p=0.16). In group B, 55 of 403 (13.6%) patients had ciprofloxacin-resistant rectal flora, while 66 (16.4%) had organisms resistant to both ciprofloxacin and gentamicin. A recent foreign travel history was associated with an increased incidence of ciprofloxacin-resistant rectal flora (23.6% vs 10.8%; p=0.007). The main limitations of our study include its retrospective nature and potential under-reporting of less severe infectious complications.

Conclusions: Rectal swab cultures identify patients with ciprofloxacin-resistant rectal flora who have an eight-fold risk of sepsis. Targeted antimicrobial prophylaxis may not be beneficial in reducing the sepsis rate when compared with augmented empirical prophylaxis. In an era of increasing antimicrobial resistance, transperineal prostate biopsies should be considered to reduce the risk of infective complications.

Patient summary: Performing rectal swab culture prior to transrectal prostate biopsy can help identify patients at risk of developing sepsis despite targeted prophylactic antibiotics.