Background Treatment options for carbapenem-resistant organism (CRO) infections remain limited, with ceftazidime/avibactam (CAZ/AVI) and polymyxin B (PMB) being the main therapeutic choices. However, comparative evidence regarding the efficacy and safety of liver transplant (LT) recipients is scarce.Methods This single-center retrospective cohort study was conducted in the liver intensive care unit of Beijing Tsinghua Changgung Hospital from January 2018 to December 2024. Adult LT recipients with CRO infections who received intravenous CAZ/AVI or PMB for > 48 h were included. Propensity score matching (PSM) was performed at a 1:1 ratio to balance baseline variables. Logistic regression analyses were used to evaluate microbial clearance, clinical success, and acute kidney injury (AKI). Cox proportional hazards models assessed the 90-day all-cause mortality and factors associated with survival outcomes.Results Among the 106 LT recipients with postoperative CRO infections, 45 received CAZ/AVI (n = 23) or PMB (n = 22). After PSM, 22 patients were included in each group. The rates of microbial clearance (59.1% vs. 63.6%), clinical success (54.6% vs. 54.6%), and 90-day all-cause mortality (22.7% vs. 27.3%) were comparable between the CAZ/AVI and PMB (p > 0.05). However, AKI occurred significantly more frequently in the PMB group than in the CAZ/AVI group (81.8% vs. 50.0%, p = 0.026). Complete withdrawal of immunosuppressive therapy was independently associated with increased 90-day mortality (hazard ratio HR = 4.46, 95% CI 1.29–15.35, p = 0.018).Conclusion CAZ/AVI and PMB achieved similar clinical effectiveness and survival outcomes in LT recipients with CRO infections; however, PMB carries a higher risk of nephrotoxicity. Discontinuation of immunosuppressive therapy during infection significantly affects patient survival. These findings highlight the importance of individualised antimicrobial selection, renal safety monitoring, and pharmacist-led stewardship in managing CRO infections in liver transplant patients.
Zhang et al. (Mon,) studied this question.