Jugular Venous Flow Healthy Volunteers

Study Overview
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Brief Summary
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Our hypothesis is that there will be a decrease in internal jugular venous flow in the park bench position when compared to the supine position. There will also be a change in blood flow in the between right and left internal jugular veins in park bench position, particularly there will be a greater reduction of flow on the dependent side. However, the internal jugular venous flow will be the same in both the prone and supine position.

Detailed Description
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The different positions used in neurosurgery (park bench, prone) for better accessibility to the operating field can impact on the cerebral venous drainage due to the effects of internal jugular venous outflow of blood and may increase intracranial pressure. The kinking of the internal jugular vein due to excessive neck flexion and rotation in park bench or flexion in the prone position may lead to kinking or twisting of the vein. This has been hypothesized as the major cause of disturbed venous drainage during surgery and in postoperative patients may lead to neck swelling, brachial plexus injury, macroglossia (swollen tongue), delayed airway obstruction and increases in intracranial pressure. Optimal brain perfusion is best in the neutral position of the head, but surgery cannot always be performed with this. Thus, we look to measure the internal jugular venous flow at different positions as there have been little studies looking at this important contributing factor.

Official Title
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Effect of Different Surgical Positions on the Cerebral Venous Drainage: an Ultrasound Study on Healthy Volunteers

Conditions
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Jugular Venous Blood Flow

Intervention / Treatment
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* Other: Different positions


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult healthy volunteers who are above the age of 18 American Society of Anesthesiologists classification (ASA) 1 Body mass index (BMI) less than and equal to 35 Exclusion Criteria: ASA 2 and above BMI above 35 Lack of informed consent Language barrier Medical students and anaesthesia residents going through the department as part of their rotation

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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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| volunteers in different positions<br>The following will be compared in the same volunteer: Bilateral internal jugular venous flow in supine and prone position Bilateral internal jugular venous flow in supine and park bench position Bilateral internal jugular venous flow in prone and park bench | Other: Different positions<br>* Jugular venous blood flow in healthy volunteers in 3 different positions- supine, prone and park bench<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Internal Jugular Venous (IJV) Cross Sectional Area | Comparisons of both jugular vein (IJV) of twenty-seven volunteers in supine and prone positions. | 1 day | 
| Right and Left IJV Cross Sectional Area | Twenty-seven volunteers were included in this study. Comparisons of cross sectional area measurements in both IJVs between supine and right park bench | 1 day | 
| Internal Jugular Venous (IJV) Doppler Velocity | 27 volunteers enrolled to measure the Internal Jugular Venous (IJV) in supine and prone positions | 1 day | 
| Bilateral Internal Jugular Vein (IJV) Flow | Comparisons of bilateral internal jugular vein (IJV) flow between supine and prone position. Data presented as mean (SD) . | 1 day | 
| Bilateral Internal Jugular Vein (IJV) Doppler Velocity | Comparisons of bilateral internal jugular vein (IJV) Doppler velocity between supine and right park bench position. | 1 day | 
| R IJV and L IJV Flow | Bilateral internal jugular vein (IJV) flow between supine and right park bench position. | 1 day |