Effects of uncomfortable care and histamine H2-antagonists on delirium in acute stroke: A propensity score analysis.

BACKGROUND AND PURPOSE: Uncomfortable care and histamine H2 antagonist (H2A) are implicated in precipitating delirium. In acute stroke, however, the need for them depends on stroke severity, an established risk factor for delirium. So, it is unclear whether care or H2A itself is responsible for delirium. We aimed to evaluate their causal effects on delirium in acute stroke patients. METHODS: This is a prospective cohort study on acute stroke patients admitted to a stroke care unit. Patients without stupor, coma, sedation, or delirium upon admission were enrolled. The treatment was H2A and five care modalities given during the first 24 h: restraint use, prohibited self-transfer, no oral feeding, indwelling catheters, and frequent nighttime care. The outcome was delirium within 5 days defined as Intensive Care Delirium Screening Checklist ≥4 points. We estimated the relative risk (RR) for delirium with regression models weighted by overlap weights using propensity scores estimated through logistic models incorporating known and potential confounders, including stroke severity. RESULTS: Of the 387 participants, 188 were given at least one care modality and 130 were given H2A. A total of 42 developed delirium. Delirium was significantly associated with prohibited self-transfer (RR 1.7, 95% CI 1.0-3.0), frequent nighttime care (RR 2.1, 95% CI 1.2-3.7), and multiple care modalities (RR 2.4, 95% CI 1.3-4.4), while other care modalities and H2A were not. CONCLUSIONS: This study showed possible causal effects of uncomfortable care on delirium and suggests that minimizing it could prevent delirium in acute stroke.

Development of a clinical score, PANDA, to predict delirium in stroke care unit.

BACKGROUND AND PURPOSE: Delirium frequently complicates acute stroke and worsens outcomes. Because delirium is potentially preventable, predicting its occurrence is essential. Although several prediction scores have been proposed, nurses need to quickly predict delirium in stroke care units (SCUs). We aimed to develop a simple tool for this purpose by examining a comprehensive set of potential predictors. METHODS: This is a prospective cohort study on acute stroke patients admitted to an SCU. Patients without stupor, coma, or delirium upon admission were eligible. Participants were followed for 5 days from admission. Delirium was defined as Intensive Care Delirium Screening Checklist ≥4 points. We examined 27 potential predictors, of which 13 predictors were used to developed a least absolute shrinkage and selection operator-penalized logistic regression model. Five variables with the largest coefficients were assigned one point each in the prediction score. The internal validation was performed by bootstrapping. RESULTS: Delirium occurred in 42 of the 387 participants. The score consisted of prior delirium, alcohol, NIHSS ≥5, dementia, and auditory/visual impairment (PANDA). The apparent AUC was 0.84 (95% confidence interval [CI], 0.78-0.89), and the optimism-corrected AUC was 0.81 (95% CI, 0.73-0.88). With a cutoff of ≥2 points, sensitivity was 0.78 (95% CI, 0.65-0.90), and specificity was 0.74 (95% CI, 0.70-0.79). CONCLUSIONS: PANDA score is simple and predicts delirium in an SCU satisfactorily.