Carbapenem-resistant Acinetobacter baumannii bloodstream infections in critically ill patients: prognostic factors and development of a nomogram

Objective: (CRAB) bloodstream infection (BSI) and to establish a personalized risk prediction model. Methods: This retrospective cohort study included 185 ICU patients with CRAB-BSI at a tertiary care hospital between 2013 and 2023. Based on 30-day outcomes, patients were categorized into survival and non-survival groups. Independent risk factors for mortality were identified through univariate and multivariate logistic regression analyses. These factors were used to construct a nomogram prediction model. Model performance was evaluated by assessing discrimination using the area under the receiver operating characteristic curve with a calibration plot, and clinical utility via decision curve analysis. Results: The 30-day mortality rate among ICU patients with CRAB-BSI was 60.0%. Multivariate analysis revealed that age [odds ratio (OR) = 1.04, 95% confidence interval (CI): 1.02-1.07], impaired consciousness (OR = 5.10, 95% CI: 2.27-11.45), prior corticosteroid use (OR = 5.82, 95% CI: 2.10-16.12), Sequential Organ Failure Assessment (SOFA) score (OR = 1.26, 95% CI: 1.12-1.42), and C-reactive protein (CRP) level (OR = 1.01, 95% CI: 1.01-1.02) were independent risk factors for 30-day mortality. A nomogram incorporating these variables achieved an area under the curve (AUROC) of 0.863 for predicting 30-day mortality risk. The calibration curve indicated excellent concordance between predictions and observed outcomes, and decision curve analysis demonstrated significant clinical net benefit over a wide range of probability thresholds. Conclusion: Mortality is high in ICU patients with CRAB-BSI and is significantly associated with age, impaired consciousness, corticosteroid use, SOFA score, and CRP level. The developed nomogram exhibits strong predictive accuracy and may function as a practical tool for quantitative management decisions.