Sympatholytic Effect of Thoracic ESP

Study Overview
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Brief Summary
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The primary endpoint of this study was to identify if erector spinae plane bloock (ESPB) demonstrates any sympatholytic effect. The secondary endpoint of this study was to compare the changes of PI value between responders and non-responders.

Detailed Description
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The erector spinae plane block (ESPB) is a less invasive, safer, and technically easy alternative procedure to conventional neuraxial anesthetic techniques. In contrast to common neuraxial techniques such as paravertebral and epidural injections, the ESPB targets an interfascial plane which is far from the spinal cord, root, and pleura. First applied to thoracic neuropathic pain, currently ESPB is being applied to postoperative pain control and includes variable clinical situations. In the abdomen and thoracic wall, thoracic ESPB can be applied for pain control after cardiac surgery, video-assisted thoracic surgery, laparoscopic cholecystectomy, and thoracotomy. Recently, favorable postoperative pain control after lumbar spinal or lower limb surgeries has been reported with lumbar ESPB. In addition, ESPB has also been used for chronic pain conditions in the upper and lower extremities. The perfusion index (PI) is a numerical value for the ratio between pulsatile and non-pulsatile blood flow measured by a special pulse oximeter. Although the special probe for PI measurement is relatively more expensive compared with ordinary pulse oximetery probes, its benefit as a marker of peripheral perfusion and as an idex for sympathetic stimulation have increased its use progressively. ESPB can achieve analgesic effect by blocking the ventral and doramal ramus and possibly by diffusion into paravertebral space. In constrast to lumar region, thoracic paravertebral space is very close to the sympathetic chain. Therefore, sympatholytic effect might be achieved by thoracic ESPB. No previous study has demonstrated the sympatholytic effect of ESPB.

Official Title
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Sympatholytic Effect of High Thoracic Erector Spinae Plane Block

Conditions
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Pain, Chronic

Intervention / Treatment
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* Procedure: Erector spinae plane block


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Complex regional pain syndrome Post-thoracotomy pain syndrome Cervical foraminal stenosis Cervical disc herniation Herpes zoster Exclusion Criteria: Pregnacy Coagulation abormality Previous spine surgery Allergy to local anesthetics

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 80 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: 20 ml T2 ESPB group<br>T2 ESPB group where ESPB is performed at T2 with local anesthetics 20ml | Procedure: Erector spinae plane block<br>* fascial plane injection guided by ultrasound<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Perfusion index changes among 4 times period | Perfusion index changes after T2 ESPB among 4 times period | baseline, 10minutes after ESPB, 20 minutes after ESPB, 30 minutes after ESPB | 
| Numerical rating scale changes among 3 times period | Numerical rating scale changes among 3 times period | baseline, 30 minutes after ESPB, 2 weeks after ESPB | 
| Perfusion index ratio at 10 minutes | Perfusion index ratio at 10 minutes | baseline, 10minutes after ESPB |