A comparative study of ceftazidime/avibactam-based and fosfomycin plus meropenem-based regimens for managing infections caused by carbapenem-resistant Klebsiella pneumoniae in critically ill patients

The main aim of this study was to compare and analyze the effectiveness of treatment regimens using ceftazidime/avibactam (CAZ/AVI) versus fosfomycin plus meropenem (FOS/MER) for managing bloodstream infections (BSI) or ventilator-associated pneumonia (VAP) caused by carbapenem-resistant Klebsiella pneumoniae (CRKP) in critically ill patients. Between 4 January 2019, and 16 July 2023, adult patients (≥18 years old) diagnosed with BSI or VAP due to culture confirmed CRKP in ICU of a tertiary care hospital were investigated retrospectively. A total of 71 patients were categorized into two groups: 30 patients in CAZ/AVI-based, and 41 patients in FOS/MER-based group. No substantial disparities were found in the total duration of ICU hospitalization, as well as the 14- and 30-day mortality rates, between patients treated with CAZ/AVI-based and FOS/MER-based therapeutic regimens. We consider that our study provides for the first time a comprehensive understanding of treatment outcomes and associated risk factors among patients with CRKP-related infections.