Effects of Head-of-Bed on Intracranial Pressure

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

Detailed Description
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The optimal positioning of the head-of-bed (HOB) has remained controversial in the neurosurgical field. Very limited data exists outlining the effects of HOB positioning in subarachnoid hemorrhage (SAH) patients. One study by Schulz-Stubner and Thiex assess the effects of HOB positioning in SAH and traumatic brain injury (TBI) patients. While this study offers some valuable insight into the changes in cerebral hemodynamics seen when the HOB changes, it congregates data from two very different pathologies. This could potentially misrepresent the true effects patients experience. A study by Kung et al. assesses cerebral blood flow dynamics and HOB changes in the setting of SAH but does not evaluate the effects on intracranial pressure (ICP) (Kung, et al., 2013). There appear to be no studies which evaluate the effect of HOB positioning on ICP in patients with SAH. No current data exists to determine if dependent leg positioning would help to further lower ICP. Theoretically, placing a patient's legs in a dependent position would lead to increased venous pooling of blood in the legs which might translate to lower ICP.

Official Title
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Response of Intracranial Pressure Based on Head-of-Bed Positioning in Aneurysmal Subarachnoid Hemorrhage

Conditions
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Subarachnoid Hemorrhage, Aneurysmal

Intervention / Treatment
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* Other: Supine
* Other: Semi-Recumbent
* Other: Semi-Recumbent with Legs Flexed


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with subarachnoid hemorrhage confirmed by CT scan, MRI, or cerebral angiogram Age ≥ 18 years old Patients with intracranial pressure monitoring device Patients with continuous arterial blood pressure monitoring The subject or legally authorized representative must be available and able to consent Exclusion Criteria: Intubated patients who are prone Patients with left ventricular ejection fraction <20% as evidenced by echocardiogram previously documented at any time in the electronic medical record Patients with a diagnosis of pulmonary hypertension Patients 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.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Positional Changes<br>The patient will begin in a supine position with the head-of-bed (HOB) at zero (0) degrees. The patient will remain in this position for five (5) minutes while pressure data is collected every fifteen (15) seconds. Next, the HOB will be adjusted to thirty (30) degrees. The patient will remain in this position for five (5) minutes while pressure data is collected every fifteen (15) seconds. Lastly, the HOB will remain at thirty (30) degrees and the foot-of-bed (FOB) will be adjusted to place the patient's leg in a dependent position. The patient will remain in this position for five (5) minutes while pressure data is collected every fifteen (15) seconds. | Other: Supine<br>* The patient will be positioned supine with head-of-bed at zero degrees.<br>Other: Semi-Recumbent<br>* The patient will be placed in a semi-recumbent position with head-of-bed at thirty degrees.<br>Other: Semi-Recumbent with Legs Flexed<br>* The patient will be placed in a semi- recumbent position with head-of-bed at thirty degrees and legs flexed.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Intracranial Pressure Change, measured in mmHg |  | Measured every fifteen seconds for twenty minutes. | 
| Cerebral Perfusion Pressure Change, measured in mmHg |  | Measured every fifteen seconds for twenty minutes. | 
| Response of Intracranial Pressure to Positional Changes During Hospitalization | The response of intracranial pressure to positional changes will be monitored during hospitalization. | During hospitalization, maximum ten sequential days. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Do Patients Experiencing Vasospasm Have Similar ICP Responses to Positional Changes? | Transcranial Doppler of Middle Cerebral Artery; Mean Velocity | Measured once per day; for up to ten days. | 
| Do Patients Experiencing Vasospasm Have Similar ICP Responses to Positional Changes? | Intracranial Pressure; measured in mmHg | Measured every fifteen seconds for twenty minutes. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Hemorrhage, Subarachnoid, Intracranial Pressure