Ultrasonographic Assessment of Neck Vessels as Predictors of Spinal Anesthesia Induced Hypotension in Elderly

Study Overview
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Brief Summary
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Spinal anesthesia induces sympathetic blockade and venodilation, thus reducing venous return and the cardiac output. Therefore, assessment of intravascular volume deficit before anesthesia might predict a critical decrease in blood pressure after anesthesia. Recently, ultrasonographic evaluation of the internal jugular vein (IJV) has been used to reflect intravascular volume status and fluid and as a predictor of hypotension after induction of general anesthesia. Carotid intima-media thickness (CIMT) has been used to predict atherosclerosis-related events, such as stroke, myocardial infarction, peripheral artery disease, and hypotension after induction of anesthesia with a cut-off value of 0.65 mm of CIMT as a threshold level.

Detailed Description
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This study aims to evaluate the ability of preoperative Ultrasonographic assessment of the internal jugular vein (IJV) and Carotid intima-media thickness (CIMT) to predict spinal anesthesia induced hypotension (SAIH). Participants will be elderly patients (above 60 years), ASA I-II-III, scheduled for elective surgeries under spinal anesthesia.

Official Title
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Pre-anesthetic Ultrasonographic Assessment of Neck Vessels as Predictors of Spinal Anesthesia Induced Hypotension in Elderly: a Prospective Observational Study.

Conditions
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Post-spinal Hypotension

Intervention / Treatment
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* Device: IJV Ultrasonography
* Device: Carotid Intima Media Thickness
* Procedure: Spinal anesthesia


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult patients (>60 years) ASA I-II-III Patients scheduled for elective surgeries under spinal anesthesia. Exclusion Criteria: Operations which will last for less than 15 minutes. Deep vein thrombosis in the upper extremities. History of radiotherapy or neck surgery. Previous sonographic data show tricuspid or mitral regurgitation or a very distended right atrium and ventricle. Patients with history of valvular or carotid artery surgery, arrhythmia, heart failure. Being unable to lie in a supine position for the necessary measurements. Technical limitations to imaging of the IJV and carotid artery.

Ages Eligible for Study
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Minimum Age: 60 Years
Maximum Age: 90 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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Arms and Interventions

| Intervention/Treatment |
| --- |
|Device: IJV Ultrasonography|Patient will be in supine position, The linear probe with frequency of 7- 12 M hz; depth of 3 cm. maximum IJV diameter (IJV-D) and area (IJV-A) will be recorded. M-mode will be used to obtain the distance between the 2 walls of the vein during inspiration and expiration. Then, the patient will be positioned 10° Trendelenburg and similar ultrasonographic measurements will be again performed|
|Device: Carotid Intima Media Thickness|US Probe is slided superiorly (toward the head) or inferiorly (toward the feet) until the bifurcation of the common carotid artery (CCA) appears on the left side of the screen. This is the ideal location for imaging and CIMT measurements. IMT is assessed in longitudinal view from the arterial far wall, along a 10mm length. CIMT will appear as two parallel lines (leading edges of two anatomical boundaries) from it: lumen- intima and media- adventitia interfaces perpendicular to ultrasound beams.|
|Procedure: Spinal anesthesia|Spinal anesthesia will be performed in the sitting position at level of L3-4 or L4- 5 interspaces with a 25-gauge spinal needle. Local infiltration of skin and subcutaneous tissue with 2% lignocaine will be applied. After confirming cerebrospinal fluid flow, 10 mg of 0.5% hyperbaric bupivacaine plus 25 mcg fentanyl will be injected. The degree of sensory block (cold test by alcohol gauze) will be assessed in the study with a goal of T8 dermatomal level block.|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Accuracy of IJV collapsibility index as predictor of Spinal anesthesia induced hypotension. | (Area under receiver operating characteristic curves) | 10 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Accuracy of rate of change in IJV area with change in posture as a predictor of Spinal anesthesia induced hypotension. | (Area under receiver operating characteristic curves) | 10 minutes | 
| Incidence of Spinal anesthesia induced hypotension | Change in mean arterial blood pressure 25% less than the preoperative baseline level. | 20 minutes | 
| Carotid intima media thickness. | IMT is measured as the distance between lumen-intima and media-adventitia interfaces | 10 minutes | 
| Norepinephrine consumption | the total dose of norepiniphrine and number of boluses | 20 minutes |