Pathogen Characterization and Prognostic Factor Analysis in Patients with Cerebral Infarction and Concomitant Pulmonary Infection

Objective: To evaluate the pathogenic characteristics and prognostic factors in patients with pulmonary infection (PI) following cerebral infarction (CI). Methods: In this retrospective study, 175 patients with pneumonia after CI were analyzed. The pathogenic bacterial profile was examined, and patients were divided into a good prognosis group (n = 116) and a poor prognosis group (n = 59) based on clinical outcomes. Univariate analysis was used to screen for potential risk factors, and those with significant differences were further evaluated by logistic regression. A nomogram was then constructed to facilitate prognostic assessment, and the model’s predictive performance was determined using the area under the receiver operating characteristic (ROC) curve (AUC). Results: A total of 169 pathogenic strains were isolated, with gram-negative bacteria accounting for 63.31% (107/169) of isolates. Multiple infections were identified in 28 patients. Acinetobacter baumannii showed a high drug resistance rate. Significant differences between the two prognostic groups were observed in terms of ICU admission, atrial fibrillation, impaired consciousness, invasive procedures, neutrophil-to-lymphocyte ratio (NLR), C-reactive protein/albumin ratio (CAR), and multiple infections (P < 0.05). Logistic regression identified atrial fibrillation, multiple infections, invasive procedures, NLR, and CAR as independent predictors of poor prognosis (P < 0.05). The predictive model had an AUC of 0.883 (95% CI: 0.828–0.937), with a sensitivity of 83.1% and a specificity of 86.2%. Bootstrap validation (1,000 resamples) yielded an AUC of 0.881 (95% CI: 0.830–0.931). Conclusions: PI following CI is mainly due to gram-negative bacteria, with a notable rate of multiple infections. Several clinical and laboratory parameters, including atrial fibrillation, multiple infections, invasive procedures, NLR, and CAR, are independently associated with prognosis. Early identification and targeted intervention for these risk factors may reduce mortality in patients with CI complicated by pulmonary infection.