NEW evidence suggests that empirical antibiotic therapy for acute cholangitis can be better tailored using microbiological data and patient characteristics, potentially improving outcomes while reducing unnecessary use of broad-spectrum antibiotics.
Acute cholangitis is a life-threatening condition in which delays or ineffective antimicrobial treatment are associated with increased mortality. Although broad-spectrum antibiotics are often used empirically, concerns remain about antimicrobial resistance and overtreatment. To address this, researchers analysed how bile and blood culture results, alongside patient-level data, could inform more effective and targeted empirical antibiotic strategies.
Microbiological Patterns in Acute Cholangitis
The study analysed 423 positive bile duct cultures and 197 corresponding blood cultures from 348 consecutive patients treated for acute cholangitis at a large tertiary referral centre. Enterobacterales and enterococci were isolated at similar frequencies in bile cultures, each accounting for approximately 30% of pathogens. In contrast, blood cultures were dominated by enterobacterales, which represented more than half of all isolates, while enterococci were less frequent.
Antibiotic resistance patterns raised important concerns. Resistance rates among enterobacterales exceeded 20% for fluoroquinolones, cephalosporins, and acylureidopenicillins, whereas resistance to carbapenems remained very low, below 2%. These findings highlight the limitations of commonly used empirical regimens in this setting.
Gaps in Empirical Coverage
Overall, the effectiveness of empirical antibiotic therapy was suboptimal. Initial treatment covered only 51% of pathogens isolated from bile cultures and 69% of those identified in blood cultures. This gap in coverage underscores the clinical risk of relying on standard empirical approaches without accounting for local resistance patterns and patient-specific risk factors.
Using multivariate logistic regression, the authors identified predictors linked to pathogen distribution, antibiotic susceptibility, and the likelihood of adequate empirical coverage. These predictors included both microbiological findings and clinical characteristics documented at presentation.
Towards Carbapenem-Sparing Strategies
While carbapenems offered the highest likelihood of effective coverage across the unselected patient population, the authors caution against their indiscriminate use. Importantly, the analysis identified distinct patient subgroups in whom carbapenem-sparing regimens could achieve excellent coverage.
For patients with community-acquired acute cholangitis who did not have biliary prostheses and did not require intensive care, piperacillin/tazobactam emerged as an effective empirical option with high expected coverage. This approach balances the need for prompt, effective therapy with antimicrobial stewardship principles.
Clinical Implications
The findings support a more nuanced approach to empirical antibiotic selection in acute cholangitis, integrating patient characteristics and local microbiological data rather than defaulting to broad-spectrum agents. The authors conclude that such stratified strategies may improve early treatment effectiveness while helping to curb the overuse of carbapenems in routine clinical practice.
Reference
Kruis T et al. Use of microbiological and patient data for choice of empirical antibiotic therapy in acute cholangitis. BMC Gastroenterol. 2020;DOI: 10.1186/s12876-020-01201-6.
