Description of Sites/Facilities Enrolling Participants: The study will take place at Oregon Health & Science University Hospital, with enrollment of patients admitted to the OHSU NSICU, a part of a comprehensive stroke center certified by the American Heart Association and Joint Commission for Accreditation of Healthcare Organizations, with a catchment area including the state of Oregon, Southwest Washington and Northern California. Approximately 80-100 patients with aneurysmal SAH are admitted each year.