Factors Associated with Short-Term Clinical Outcomes in ICU Patients with Carbapenem-Resistant Acinetobacter baumannii Pneumonia: A Single-Center Retrospective Cohort Study

Background: Carbapenem-resistant Acinetobacter baumannii (CRAB) infections carry a high mortality rate, yet effective treatments remain scarce. CRAB infections have become increasingly common in intensive care units (ICUs), but data specifically examining CRAB pneumonia in ICU patients remain limited. This study aimed to identify factors associated with in-hospital mortality and day-14 clinical failure in ICU patients with CRAB pneumonia. Methods: Data from 173 ICU patients with CRAB pneumonia admitted to a tertiary referral hospital in the Republic of Korea between January 2018 and June 2025 were retrospectively analyzed. Multivariable logistic regression was used to identify factors independently associated with in-hospital mortality and day-14 clinical failure. Results: The median patient age was 70 years, and ventilator-associated pneumonia accounted for 76.3% of cases. In-hospital mortality reached 80.9% (140/173), and 75.7% (131/173) experienced clinical failure at day 14. After adjustment, higher serum albumin was associated with lower in-hospital mortality (odds ratio OR, 0.55; 95% confidence interval CI, 0.31–0.95; p = 0.031), whereas corticosteroid use was associated with higher mortality (OR, 2.82; 95% CI, 1.23–6.50; p = 0.015). However, in an exploratory dose-based analysis among patients who received corticosteroids, prednisone-equivalent dose was not significantly associated with in-hospital mortality. For day-14 clinical failure, higher C-reactive protein and higher Sequential Organ Failure Assessment scores were associated with increased failure, while minocycline use was associated with reduced failure (OR, 0.21; CI, 0.08–0.50; p = 0.001). Conclusions: Lower albumin levels and corticosteroid use were independently associated with higher in-hospital mortality among ICU patients with CRAB pneumonia. Minocycline may offer clinical benefit, although further validation is needed.