Prevalence and clinical implications of altered mental status in patients with infection presenting to the emergency department.

The prevalence and clinical implications of altered mental status among patients presenting with infection to the emergency department (ED) remain unclear. This retrospective cohort study, which enrolled consecutive patients with infection aged ≥ 15 years who presented to the ED between January and June 2024 and underwent blood culture collection, was aimed at determining the prevalence of altered mental status, identifying associated clinical factors, and assessing its impact on mortality outcomes. Patients were stratified according to the presence or absence of altered mental status at ED presentation. Clinical characteristics were compared between groups and multivariable logistic regression analysis was performed to identify factors independently associated with altered mental status. Of the 767 patients included, 152 (20%) presented with altered mental status. In-hospital mortality was significantly higher in this group than in the control group (15 vs. 4%; P < 0.001). Multivariable logistic regression analysis identified the following independent predictors of altered mental status: advanced age [odds ratio (OR), 1.04; 95% confidence interval (CI), 1.02-1.06], history of cerebrovascular disease (OR, 2.52; 95% CI 1.45-4.36), dementia (OR, 3.57; 95% CI 2.04-6.23), mental disorders (OR, 3.90; 95% CI 1.17-13.00), bacteremia (OR, 2.49; 95% CI 1.39-4.46), and higher Sequential Organ Failure Assessment scores (OR, 1.31; 95% CI 1.20-1.42). Altered mental status is common among ED patients with infection, reflecting both infection severity and baseline patient vulnerability. Its association with increased in-hospital mortality highlights the importance of early recognition and comprehensive assessment of mental status changes in this patient population.