Evaluation of Infections Caused by Carbapenem-Resistant Pseudomonas aeruginosa, Acinetobacter baumannii, and Klebsiella pneumoniae in an Intensive Care Unit: A Retrospective Study

<b>Objectives:</b> Carbapenem-resistant Gram-negative bacteria (CR-GNB) infections in intensive care units (ICUs) are increasingly prevalent and associated with high mortality. This study aimed to investigate the distribution of isolated bacteria and determine the factors associated with mortality among ICU patients diagnosed with CR-GNB infections. <b>Methods:</b> This retrospective study included 95 patients admitted to the ICU between February 2022 and July 2024 who were diagnosed with CR-GNB infections via culture and initiated on treatment. Thirty-day mortality was defined as the clinical outcome, and patients were divided into two groups: survivors (Group 1, <i>n</i> = 42) and deceased (Group 2, <i>n</i> = 53). Demographic, clinical, laboratory, and microbiological data were analyzed. <b>Results:</b> Advanced age, the presence of malignancy, an elevated Charlson Comorbidity Index (CCI), lower platelet counts, and higher C-reactive protein (CRP) levels were significantly associated with mortality (<i>p</i> < 0.05). Trauma-related admissions were more common among survivors, while sepsis-related admissions predominated among non-survivors. No statistically significant associations were observed between antibiotic regimen type and mortality. Culture-based pathogen distribution revealed <i>A. baumannii</i> as the predominant organism in respiratory samples, while <i>K. pneumoniae</i> was more frequently isolated from bloodstream and urinary specimens. <b>Conclusions:</b> Mortality in ICU patients with CR-GNB infections is influenced by both baseline comorbidities and infection-related inflammatory markers. This study provides region-specific insights from a high-resistance ICU setting and may inform risk stratification, prognostication, and management strategies in critically ill patients with CR-GNB infections.