Ceftazidime–avibactam for carbapenem-resistant Klebsiella pneumoniae infections: determining mortality predictors in the intensive care unit

Abstract Background Carbapenem-resistant Klebsiella pneumoniae (CRKP) represent a significant global threat. The objective of this study is to provide a comprehensive description of the clinical course and outcomes of patients with CRKP infections treated with ceftazidime avibactam (CAZ-AVI) in comparison to patients treated with alternative agents. Methods A retrospective cohort study was conducted on patients diagnosed with CRKP infection between November 2022 and January 2025.The present study comprised all patients treated with CAZ-AVI in the intensive care unit and clinical cultures in which carbapenem-resistant isolates were detected.Patients were divided into two groups: those treated with CAZ-AVI and those receiving alternative combination antibiotic therapies. The clinical efficacy of CAZ-AVI treatment and its effect on mortality were evaluated by comparing these groups. Results A total of 249 patients were included in the study, of whom 115 received CAZ-AVI and 134 were assigned to the comparator group. The two groups were comparable in terms of age ( p = 0.236) and comorbidities. Patients treated with CAZ-AVI demonstrated significantly lower mortality at days 7, 14, and 28 compared with the comparator group ( p = 0.011, p < 0.001, and p < 0.001, respectively). However, in multivariable analyses, CAZ-AVI treatment was not independently associated with mortality at days 7, 14, or 28 ( p = 0.201, p = 0.105, and p = 0.175, respectively). Advanced age was independently associated with 14- and 28-day mortality ( p = 0.016 and p = 0.018, respectively), while diabetes mellitus ( p = 0.038), low lymphocyte count ( p = 0.002), and hypoalbuminemia ( p = 0.029) were independently associated with 28-day mortality. Conclusions A substantial enhancement in the early survival of patients treated with CAZ-AVI was evident, yet this correlation was found to be insignificant in multivariate analyses. This observation indicates that the observed survival benefit may be partially attributable to variations in baseline clinical characteristics rather than an independent treatment effect. The mortality rate in critically ill KP-BSI patients is attributable to a multitude of disease-related risk factors, and the mortality rate in CRKP patients underscores the necessity for rational, evidence-based antibiotic management, as well as effective and continuous surveillance strategies.