Predictors of delirium in thrombolysed patients

Abstract

Background: Delirium is a common complication after acute ischemic stroke and is associated with worse outcomes. However, few studies have prospectively evaluated the specific clinical factors that predict the occurrence of delirium among patients treated specifically with intravenous thrombolysis. Objective: To determine clinical characteristics independently associated with the development of in-hospital delirium in patients with acute ischemic stroke treated with intravenous thrombolysis. Methods: We conducted a prospective cohort study including adults with acute ischemic stroke treated with intravenous thrombolysis and admitted to a tertiary stroke unit in Northeastern Brazil between April 2023 and March 2026. Delirium was systematically assessed from admission to discharge using the Confusion Assessment Method for the Intensive Care Unit. Multivariable logistic regression was used to estimate adjusted odds ratios (aOR) and 95% confidence interval (CI). The model included age, any hemorrhagic transformation (HT), NIHSS on admission, ictus-thrombolysis time, systolic blood pressure (SBP) at admission, and Short Informant Questionnaire on Cognitive Decline in the Elderly (Short IQ-CODE) score. Model discrimination was assessed using the area under the receiver operating characteristic curve (AUC). Results: 332 thrombolysed patients were included in the analysis. Median age was 67 years (57-74), median NIHSS on admission was 10 (7-15), HT occurred in 44 patients (13.25%), median ictus-thrombolysis time were 210 minutes (170-260), and delirium occurred in 84 (13.25% ) patients from the sample. Multivariable adjustment demonstrated older age (aOR 1.007; 95% CI, 1.003-1.010; p<0.001), HT (aOR 1.219; 95% CI, 1.064-1.398; p=0.004), and baseline NIHSS score (aOR 1.029; 95% CI, 1.019-1.038; p<0.001) were identified as independent predictors of delirium. Ictus-thrombolysis time (aOR 1.00; 95% CI, 1.000-1.001; p=0.517), SBP at admission (aOR 1.002; 95% CI, 1.000-1.004; p=0.096), and Short IQ-CODE score (aOR 1.053; 95% CI 0.961-1.153; p=0.271) did not reach statistical significance. The predictive model demonstrated an AUC of 0.7948 (95% CI, 0.7346-0.855). Conclusion: Delirium after intravenous thrombolysis is independently predicted by older age, the occurrence of hemorrhagic transformation, and higher baseline NIHSS scores. Those findings may help identify high-risk patients for delirium and represent a potential target for improving post-stroke management.