Epidural Catheter Colonization Is Not Associated with Infection

Background: Epidural anesthesia is one of the most common types of regional anesthesia. Although retrospective reviews suggest that the incidence of infection from short-term epidural catheter use is exceedingly low in patients undergoing surgery, the correlation between epidural catheter cultures and infection has not been well defined. The purpose of this study was to determine the frequency of bacterial colonization of epidural catheters in adult patients undergoing surgery under epidural anesthesia, as well as the correlation between epidural catheter cultures and infection.Methods: A prospective nonrandomized study was conducted over a period of 28 months. The incidence of bacterial contamination after epidural catheterization and the correlation between epidural catheter cultures and infection was investigated for 245 adult ASA I, II patients undergoing surgery under lumbar epidural anesthesia. Catheters were removed when epidural analgesia was no longer required, or if clinical signs of infection or catheter malfunction were present. All epidural catheters were cultured upon withdrawal.Results: Epidural catheters were kept in place for 2.3 ± 0.2 days (range 0.1–12 days). Bacteriological analysis of the 245 epidural catheters yielded 28% positive cultures. The most prevalent microorganism was Staphylococcus epidermidis (58%). In obstetric operations a frequency of 32% positive cultures was observed. Neither central nervous system nor systemic infections occurred during the study. No correlations were found among the type of surgery, the type of antibiotic administration, the sex or age of the patients, the duration of catheter placement, the maximum body temperature, and the frequency of positive epidural catheter cultures. There was no correlation between epidural catheter colonization and infection.Conclusion: The contamination of epidural catheters was found to be independent of the administered antimicrobial agents prior to surgery, the duration of catheter placement, and the presence of fever. Except for perioperative prophylaxis, therapeutic use of antibiotics for short-term epidural catheters is not recommended.