A Comparative Study of Ceftazidime-Avibactam and Meropenem-Based Regimens in the Treatment of Carbapenem-Resistant...

This study aimed to compare mortality rates and treatment efficacy between ceftazidime-avibactam (CAZ/AVI) and meropenem-based combination regimens in critically ill patients with carbapenem-resistant Gram-negative bacteria (CRGNB) infections.

This retrospective study included 135 intensive care unit (ICU) patients diagnosed with CRGNB infections between 2020 and 2024. Patients were categorized on the basis of treatment: CAZ/AVI or alternative combinations that included meropenem with either amikacin or polymyxin. The primary outcomes were 14-day, 30-day, and 90-day all-cause mortality rates. The secondary outcomes included the clinical response on day 14 and the total duration of ICU hospitalization.

Among the patients, 74 received CAZ/AVI, whereas 61 were treated with meropenem-based regimens. No significant differences were observed in the baseline characteristics between the groups. There were no statistically significant differences in 14-day (27.0% vs. 31.1%), 30-day (41.9% vs. 47.5%), or 90-day mortality rates (62.2% vs. 65.6%) between the two groups (p = 0.738, 0.511, and 0.818, respectively), including within the pneumonia and bloodstream infection subgroups. Clinical success was observed in 64.9% of the CAZ/AVI group and 65.6% of the other group (p = 0.931), with comparable ICU lengths of stay (44.0 ± 29.1 vs. 41.5 ± 26.4 days, p = 0.974). Multivariate analysis revealed that advanced age, higher Sequential Organ Failure Assessment (SOFA) scores, elevated procalcitonin levels, and prolonged time from culture collection to the initiation of appropriate antibiotic therapy were independent predictors of increased 30-day mortality.

CAZ/AVI demonstrated efficacy and mortality outcomes comparable to those of meropenem-based regimens in ICU patients with CRGNB infections. Prompt initiation of appropriate antimicrobial therapy remains critical.