Use of the bilateral BIS monitor as an indicator of cerebral vasospasm in ICU patients.

Earlier diagnosis of cerebral vasospasm and delayed cerebral ischemia (DCI) and treatment has the potential to decrease post-bleed morbidity after subarachnoid hemorrhage (SAH). Previous studies have shown that electroencephalogram (EEG) can detect blood flow changes associated with DCI sooner than other modalities potentially leading to earlier diagnosis. However, continual monitoring with raw EEG requires significant expertise and effort, and may be difficult due to the intermittent need for MRI studies in these patients. Here we describe a series of patients with subarachnoid hemorrhage in the Neurosurgical ICU who underwent monitoring with the Bilateral Bispectral Index (BIS) monitor.