Efficacy of cefoperazone-sulbactam as a component of combination therapy for carbapenem-resistant Acinetobacter baumannii bloodstream infection in intensive care units: a multicenter retrospective propensity score-matched study

Background In this study, we aimed to evaluate the efficacy of cefoperazone-sulbactam-containing (CSC) combination therapy for carbapenem-resistant Acinetobacter baumannii (CRAB) bloodstream infections (BSI) patients in intensive care unit (ICU). Methods This multicenter, retrospective cohort study initially included 407 patients with CRAB BSI in the ICU between 2015 and 2019. Patients were divided into the CSC- and non-cefoperazone-sulbactam-containing (NCSC) groups. Outcomes including mortality, clinical failure, and microbiological eradication were compared after time-window bias adjustment and propensity score matching. Results There was no statistical difference in baseline characteristics and disease severity between the CSC (n = 50) and NCSC groups (n = 150) after propensity score matching. The CSC group had significantly lower rates of all-cause mortality (30.0% vs. 50.0%, p = 0.014) and clinical failure (32.0% vs. 52.0%, p = 0.015) on day 28 than the NCSC group. The CSC regimen was an independent protective factor against 28-day clinical failure (adjusted odds ratio (aOR) = 0.281, 95% confidence interval [CI] = 0.091-0.864, p = 0.027). Kaplan-Meier analysis showed that the CSC group had a significantly longer survival time than the NCSC group (log-rank test, p = 0.028). The subgroup analysis of clinical factors associated with 28-day mortality showed that female patients and those with body mass index > 25, non-smoker status, and C-reactive protein < 30 especially favored the CSC regimen instead of the NCSC regimen. Conclusions As an alternative to ampicillin-sulbactam, cefoperazone-sulbactam could be considered as components of combination therapy for critically ill patients with CRAB BSI.