Rate and risk factors for a hyperactivity delirium in patients with aneurysmal subarachnoid haemorrhage

Hyperactive delirium (agitation) is a common complication in patients on intensive care units and can be assessed by the Richmond Agitation and Sedation Scale (RASS) in principle. However, the role of agitation in patients with aneurysmal subarachnoid haemorrhage (SAH) is poorly understood. We performed a retrospective analysis to identify risk factors for the development of a hyperactive delirium and its functional consequences for neurological outcome. Three hundred thirty-eight patients with SAH were screened in this study resulting in 212 patients which reached at least once a RASS of 0 and were eligible for further analysis. Clinical characteristics were analysed towards the occurrence of a hyperactive delirium. Neurological outcome at discharge and follow-up was assessed using the Glasgow Outcome Scale. Seventy-eight of 212 patients (36.8%) developed a hyperactive delirium; the duration ranged from 1 to 11 days. Multivariate regression revealed initial hydrocephalus (odds ratio (OR) 3.21 95% confidence interval (CI) [1.33-7.70]; p = 0.01), microsurgical clipping (OR 3.70 95%CI 1.71-8.01]; p = 0.001), male gender (OR 1.97 95%CI [1.05-3.85]; p = 0.047) and a higher Graeb score (OR 1.11 95%CI [1.00-1.22]; p = 0.043) to be significantly associated with the development of agitation. Medical history of psychiatric disorders, alcohol or nicotine abuse showed no correlation with agitation. Cox regression analysis revealed no significant influence of agitation towards unfavourable outcome at discharge or follow-up. We provide four independent risk factors for the development of agitation in SAH patients. Our study emphasizes the specific entity of agitation in patients with SAH and underscores its relevance in neurological patients.