Jugular Venous Flow Healthy Volunteers

Completed

Brief Summary: 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: 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.

Recruitment & Eligibility

Inclusion Criteria

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

Arm && Interventions

Group	Intervention	Description
volunteers in different positions	Different positions	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

Primary Outcome Measures

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