Comparison of Volumes of Local Anesthetics on the Efficiency and Safety of Stellate Ganglion Block for CRPS of the Arm

Study Overview
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Brief Summary
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The purpose of this study is to compare the efficiency and safety of 2ml versus 5ml of local anesthetics used in stellate ganglion blocks for the treatment of complex regional pain syndrome of the arm.

Detailed Description
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To evaluate if 2ml of 0.2% ropivacaine is less effective in decreasing pain scores by more than 50% when compared to 5ml of 0.2% ropivacaine. To evaluate if 2ml of 0.2% ropivacaine is causes less side effects when compared to 5ml after a stellate ganglion block.

Official Title
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Comparison of Two Volumes of Local Anesthetics on the Efficiency and Safety of Stellate Ganglion Block for the Treatment of Complex Regional Pain Syndrome of the Arm

Conditions
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Complex Regional Pain Syndromes

Intervention / Treatment
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* Procedure: stellate ganglion block with ropivacaine 0.2% 5 mL
* Procedure: stellate ganglion block wit ropivacaine 0.2% 2 mL


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with a diagnosis of complex regional pain syndrome of the arm according to the Budapest criteria and having already received a minimum of 3 stellate ganglion blocks. Only patients having received a minimum of 3 stellate ganglion blocks will be included since it is expected to have a progressive and sustained decrease in pain scores during the first 3 blocks. ASA 1 to 3 included Exclusion Criteria: Patient refusal Contra-indications to the stellate ganglion block procedure such as coagulopathy, anticoagulants or anti platelet therapy other than aspirin, systemic or injection site infection, important neck deformity (post-radiotherapy or surgery, etc.), severe chronic obstructive pulmonary disease, contralateral diaphragm paralysis or contralateral pneumonectomy Allergy to local anesthetics Concomitant pain syndrome other than complex regional pain syndrome of the arm Liver or kidney failure (CrCl < 30 ml/min) Inability to understand à verbal numeric pain score scale after careful explanations Inability to consent

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: Crossover Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Group 5<br>stellate ganglion block with ropivacaine 0.2% 5 mL | Procedure: stellate ganglion block with ropivacaine 0.2% 5 mL<br>* Each patient will undergo two stellate ganglion blocks and receive both volumes of local anesthetics in random order. The stellate ganglion blocks will be separated by 3 weeks in order to assure that no residual effects from the previous block will influence the results.<br>|
| Active Comparator: Group 2<br>stellate ganglion block wit ropivacaine 0.2% 2 mL | Procedure: stellate ganglion block wit ropivacaine 0.2% 2 mL<br>* Each patient will undergo two stellate ganglion blocks and receive both volumes of local anesthetics in random order. The stellate ganglion blocks will be separated by 3 weeks in order to assure that no residual effects from the previous block will influence the results.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain score | Evaluate the efficiency of stellate ganglion block in decreasing pain scores 24 hours after the procedure using a verbal numeric pain rating scale. | 24 hours after the stellate ganglion block | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain score | Evaluate the efficiency of stellate ganglion block in decreasing pain scores 7 days after the procedure using a verbal numeric pain rating scale. | 7 days after the stellate ganglion block | 
| Pain score | Evaluate the efficiency of stellate ganglion block in decreasing pain scores 14 days after the procedure using a verbal numeric pain rating scale. | 14 days after the stellate ganglion block | 
| Temperature increase in the ipsilateral arm | Evaluate the efficiency of stellate ganglion block on the increase in temperature of the ipsilateral arm using an infrared thermometer. The cutaneous temperature will be measured in order to determine the proportion of patients in each group reaching an increase of >1.5 C in the ipsilateral arm. | 1 hour after the procedure | 
| Horner Syndrome | Evaluate the efficiency of stellate ganglion block to produce an ipsilateral Horner Syndrome as defined by a ptosis and miosis. Evaluate the proportion of patients in each group presenting an ipsilateral Horner syndrome. | 1 hour after the procedure | 
| Occurrence of dysphagia after a stellate ganglion block | Patients describing having dysphagia after the stellate ganglion block | 1 hour after the procedure | 
| Occurrence of hoarseness after a stellate ganglion block | patients describing having hoarseness after a stellate ganglion block | 1 hour after the procedure | 
| Occurrence of foreign body sensation after a stellate ganglion block | patients describing having a foreign body sensation after the stellate ganglion block | 1h after the procedure | 
| Occurrence of dyspnea after a stellate ganglion block | patients describing having dyspnea after a stellate ganglion block | 1h after the procedure | 
| Occurrence of ipsilateral arm weakness after a stellate ganglion block | patients describing having ipsilateral arm weakness after a stellate ganglion block | 1h after the procedure | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Stellate Ganglion, Local Anesthetic