Effectiveness Comparison Between Ceftazidime-Avibactam and Carbapenem-Based Regimens in Nosocomial Carbapenem-Resistant Klebsiella pneumoniae Bloodstream Infections

Carbapenem-resistant Klebsiella pneumoniae bloodstream infections (CRKP BSI) are associated with high mortality rates and limited treatment options. This study compared the outcomes between ceftazidime-avibactam and carbapenem-based regimens in patients with nosocomial CRKP BSI. This is a single-center, retrospective, observational study that analyzed adult patients with nosocomial CRKP BSI from January 2018 to December 2023. Patients were divided into ceftazidime-avibactam (n = 47) and carbapenem-based regimen (n = 54) groups. Primary outcomes included 7-, 14-, 21-, and 28-day mortality rates, microbiological cure rates, and length of hospital stay. Multivariate analysis was performed to identify factors associated with mortality. The ceftazidime-avibactam group showed significantly lower 7-day mortality (8.51 % vs. 25.93 %, p = 0.043) and higher survival rates in Kaplan-Meier analysis (p = 0.021). Multivariate analysis revealed that ceftazidime-avibactam significantly reduced 7-day mortality (adjusted hazard ratio: 0.182, 95 % CI: 0.050-0.660, p = 0.010). Leukemia significantly increased both 7-day and all-cause mortality. Elevated white blood cell counts, and C-reactive protein levels were associated with increased mortality risk. Ceftazidime-avibactam demonstrated superior short-term survival benefits compared to carbapenem-based regimens in treating nosocomial CRKP BSI. However, long-term outcomes were more influenced by underlying conditions and inflammatory status.