Incidence and risk factors of delirium in patients with acute ischaemic stroke.

Abstract

Abstract Background & Objectives: The reported incidence of post-stroke delirium varies substantially in current medical literature. The impact of delirium on mortality and morbidity is significant and there is need for sustained research on the topic. We aimed to determine the incidence, risk factors and outcome of delirium in acute ischaemic stroke. Methods: We conducted a cross-sectional observational study on consecutive patients with ischaemic stroke. The Confusion Assessment Method was used to diagnose delirium within seven days of stroke onset. Results: Two hundred and eighty patients were recruited (mean age 63.6 years) and 36 (12.9%) developed delirium. After adjustments for covariates, age >65 years (odds ratio, OR 5.2; 95% confidence interval 1.6-17.5); pre-existing dementia (6.5; 1.1-38.2); TACI (7.2; 1.5-35); and a National Institute of Health Stroke Scale of ≥10 (6.8; 1.7-26.4), were independently associated with a risk of developing delirium. Lacunar infarcts were not associated with delirium (0.07; 0.03-0.16). The majority of patients with delirium were cared for in a dedicated stroke unit but this proportion was not significant compared to those without delirium (69.4% vs 58.2%, p=0.20). Delirious patients had significantly higher in-patient mortality (8.3% vs 0%, p=0.002) and longer length of hospital stay (6.94 vs 3.98 days, p< 0.001). Conclusions: One in 8 patients with ischaemic stroke in our centre developed delirium. Older age, pre-existing dementia and severe stroke were independent predictors of delirium. Patients with lacunar infarcts did not develop delirium as often as those with other stroke types. Delirium significantly increased in-patient mortality and length of hospital stay.