Effects of Head-of-Bed on Intracranial Pressure

The purpose of this study is to evaluate how pressure inside the skull responds to position changes in patients with brain bleeds.

Inclusion Criteria:Patients with subarachnoid hemorrhage confirmed by CT scan, MRI, or cerebral angiogramAge ≥ 18 years oldPatients with intracranial pressure monitoring devicePatients with continuous arterial blood pressure monitoringThe subject or legally authorized representative must be available and able to consentExclusion Criteria:Intubated patients who are pronePatients with left ventricular ejection fraction <20% as evidenced by echocardiogram previously documented at any time in the electronic medical recordPatients with a diagnosis of pulmonary hypertensionPatients with a diagnosis of cirrhosis and/or evidence of liver failure. Evidence of liver failure will be assessed by the presence of ascites, edema, abnormal lab values including low albumin, elevated PTT, elevated PT, elevated INR, or elevated bilirubin without another etiology, or MELD score >8.Patients who are clinically unstable defined as those who are unable to lie flat for 30 minutes for any reason, patients on more than one continuous IV medications to increase blood pressure, or patients who are actively undergoing resuscitation.