Validity of antimicrobial therapy for acute cholangitis administered for ≦2 days post-ERCP Young Award

Background: To prevent the increase of resistant bacteria, it is important to minimize the use of antimicrobial agents. Studies have found that administration for ≦3 days after successful ERCP is appropriate. Therefore, the present study aimed to verify if this can be further shortened to ≦2 days after ERCP. Methods: Patients who underwent successful ERCP from January 2018 to June 2020, we selected 390 patients with mild/moderate cholangitis, had positive blood or bile cultures. The antimicrobial administration period was either ≦2 days counting the day ERCP was performed (short group) or ≧3 days (long group), which were compared retrospectively. The following outcomes were compared: rate of increase in severity after hospitalization, National Early Warning Score (NEWS), in-hospital mortality rate, hospital stay, and 3-month recurrence. Risk factors for an increase in severity after hospitalization were examined using logistic regression analysis. Results: Of the 390 patients, 59 (15.1%) were in the short group, and 331 (84.9%) were in the long group. There were no differences between the groups in patient characteristics. The hospital stay was significantly shorter in the short group, but there were no differences in the other outcomes. In the logistic regression analysis, being ≧80 years old was identified as a risk factor for increase in severity but a short group was not. Conclusion: Although attention should be paid to elderly patients, if ERCP is successful in patients with acute cholangitis in mild or moderate cases, antimicrobials ≦2 days after ERCP are acceptable.