The purpose of this research study is to determine if the diameter and flow of the superior mesenteric artery in patients with aneurysmal subarachnoid hemorrhage undergoing hypertensive therapy for cerebral artery vasospasm are effected enough to justify withholding enteral nutrition.

Study measurements of the diameter and Doppler flow velocity of the superior mesenteric artery (SMA) using abdominal ultrasound in order to evaluate the potential additional risk of non-occlusive mesenteric ischemia (NOMI) and non occlusive bowel necrosis (NOBN) in patients undergoing hypertensive therapy for cerebral vasospasm in Aneurysmal Subarachnoid Hemorrhage (aSAH), to justify the withholding of enteral nutrition.

Inclusion Criteria:

• Patient diagnosed with aSAH

Exclusion Criteria:

• Hemodynamic instability
• Already receiving vasopressor therapy
• Non-aneurysmal SAH
• Intracranial hemorrhage of other cause
• Not anticipated to receive hypertensive therapy with vasoactive medications for cerebral vasospasm from SAH or suspected aSAH
• Unable to visualize SMA using ultrasound
• Pregnancy

Subjects will be recruited from the neurointensive care unit (NICU).Patients admitted to the neurointensive care unit (NICU) with a diagnosis of aSAH or are diagnosed with aSAH while an inpatient at the NICU at and area hospital.