Targeted Antimicrobial Prophylaxis Does Not Always Prevent Sepsis after Transrectal Prostate Biopsy

Purpose: We compared the effectiveness of targeted prophylaxis to augmented empirical prophylaxis and single agent empirical prophylaxis to prevent sepsis after transrectal prostate biopsy. Materials and Methods: We retrospectively reviewed the records of transrectal prostate biopsies performed during 3 years at 13 Southern California Kaiser Permanente® departments of urology. Targeted prophylaxis was guided by rectal culture bacterial susceptibility for use of a single prophylactic antibiotic while for empirical prophylaxis 1 antibiotic (single agent empirical prophylaxis) or multiple antibiotics (augmented empirical prophylaxis) were given according to the usual practice of the urologist. Sepsis was the primary outcome analyzed. Results: We reviewed 15,236 transrectal prostate biopsy cases. Targeted prophylaxis, single agent empirical prophylaxis and augmented empirical prophylaxis were administered in 26%, 58% and 16% of cases, respectively. The overall incidence of post-biopsy sepsis was 0.64%. On multivariable analysis there was no significant difference in the rate of post-biopsy sepsis after targeted prophylaxis compared to empirical prophylaxis (single agent and augmented empirical prophylaxis together) (OR 0.86, 95% CI 0.53–1.41, p = 0.561). However, on subanalysis augmented empirical prophylaxis showed a significantly lower incidence of sepsis than single agent empirical or targeted prophylaxis (OR 0.35, 95% CI 0.16–0.76, p = 0.008). Based on blood and urine cultures 38% of the patients with sepsis after transrectal prostate biopsy had been given the correct prophylactic antibiotic prior to biopsy. On multivariable analysis Asian/Pacific Islander or Hispanic/Latino ethnicity was associated with a higher incidence of harboring fluoroquinolone resistant bacteria on rectal swab cultures. Conclusions: This large retrospective study showed that augmented empirical prophylaxis was statistically superior to single agent empirical and targeted prophylaxis. Sepsis developed in a significant number of patients despite being given a prophylactic antibiotic to which the sepsis causing bacteria were sensitive.