Impact of the Ultrasound-guided Approach on the Efficiency and Safety of the Stellate Ganglion Block in Chronic Pain

Study Overview
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Brief Summary
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The first purpose of this study is to compare the effectiveness of the stellate ganglion block realized with two different approaches (blind and ultrasound-guided) in patients with a diagnosis of complex regional pain syndrome. The second purpose of this study is to determine the safest approach and to compare the safety profiles of the two approaches.

Detailed Description
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To evaluate whether the ultrasound guided approach is more effective than the blind technique in producing a greater than 1.5 degree Celsius rise in ipsilateral arm temperature after a stellate ganglion block. Blocks will both be performed with 10 mL of xylocaine/bupivacaine. Secondary outcomes will be the impact of the approach (blind vs ultrasound) on pain reduction, horner syndrome, side effects (hoarseness, dysphagia, pharyngeal discomfort) and complications (blood aspiration, intravascular injection).

Official Title
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Impact of the Ultrasound-guided Approach on the Efficiency and Safety of the Stellate Ganglion Block in Chronic Pain

Conditions
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Complex Regional Pain Syndromes

Intervention / Treatment
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* Procedure: Blind technique
* Procedure: Ultrasound-guided technique


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients aged 18 to 80 years Patients with a new or known diagnosis of complex regional pain syndrome (according to the criteria of Budapest) at the upper extremity Exclusion Criteria: Refusal of a patient Coagulopathy Systemic infection or local infection at the needle injection site Major deformation at the level of the neck (radiotherapy, surgery, etc. ) Concomitant chronic pain syndrome Post-pneumonectomy on the controlateral side Severe hepatic impairment or severe renal impairment (Clcr under 30 ml/min) Known allergy to local anesthetics of amide type Inability to understand a numeric pain scale

Ages Eligible for Study
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Minimum Age: 18 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
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Blind technique<br>Stellate ganglion block using the anterior paratracheal approach using surface landmarks. | Procedure: Blind technique<br>* A mixture of 3 mL of 2% lidocaine and 7 mL of 0.5% bupivacaine is used for both approaches (blind and ultrasound-guided).<br>|
| Active Comparator: Ultrasound-guided technique<br>Stellate ganglion block using the ultrasound-guided lateral approach at the sixth cervical vertebral level. | Procedure: Ultrasound-guided technique<br>* A mixture of 3 mL of 2% lidocaine and 7 mL of 0.5% bupivacaine is used for both approach (blind and ultrasound-guided).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| proportion of patients reaching >1.5 °C rise in ipsilateral arm temperature |  | thirty minutes after block | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Complications | Seizure, loss of consciousness with apnea, hematoma, recurrent laryngeal nerve injury, phrenic nerve paralysis, pneumothorax, weakness of the ipsilateral upper limb, foreign body sensation | Time of the block to one week after the block |