Looking for Minimum Dose to Induce Sympathectomy in Infraclavicular Brachial Plexus Block

Study Overview
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Brief Summary
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For patients who undergoing hemodialysis, it is important to have good AV fistula. One third of AV fistula usually fail during early stage. It is helpful to use nerve block to dilate the blood vessels and enhance the prognosis. But 0.2% Ropivacaine usually cause muscle weakness in present studies. The investigators hope to find the lowest concentration to provide sympathectomy without muscle weakness. Because the patients with hemodialysis usually have multiple co-morbidity, thus we choose patients with forearm fracture at the first place. With this result, the investigators can design further study for patients with hemodialysis. The investigators prefer proximal approach because brachial plexus run together in the cosctoclavicular space and show lower incidence of incomplete work.

Official Title
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Looking for Minimum Dose to Induce Sympathectomy in Infraclavicular Brachial Plexus Block

Conditions
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Finding the Minimum Dose to Induce Sympathectomy in Infraclavicular

Intervention / Treatment
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* Procedure: Infraclavicular brachial plexus block


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age between 20-80 y/o, BW: 40-90 kilograms，ASA class I-III，No pre-existing neuropathy，Scheduled for upper limb surgery. Exclusion Criteria: Pre-existing neuropathy (ex: polyneuropathy) History of allergy to xylocaine、ropivacaine、epinephrine Emergent surgery Coagulopathy Patient who can not express themselves

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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Arms and Interventions

| Intervention/Treatment |
| --- |
|Procedure: Infraclavicular brachial plexus block|Ultrasound-guided infraclavicular brachial plexus block|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of diameter of basilic vein and brachial artery | Use ultrasound to measure the difference of diameter at different time point. | Change from baseline diameter(pre-nerve block) at 45min | 
| Change of diameter of basilic vein and brachial artery | Use ultrasound to measure the difference of diameter at different time point. | Change from baseline diameter(pre-nerve block) at 24hour | 
| Change of diameter of basilic vein and brachial artery | Use ultrasound to measure the difference of diameter at different time point. | Change from baseline diameter(pre-nerve block) at 48hour | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Sensory block of upper limb | A validated 3-point scale was used: 0 = no block (patient has normal sensation), 1 = patient can feel cold, but the sensation is reduced compared with the unblocked side, and 2 = complete anesthesia. | 45min post nerve block | 
| Sensory block of upper limb | A validated 3-point scale was used: 0 = no block (patient has normal sensation), 1 = patient can feel cold, but the sensation is reduced compared with the unblocked side, and 2 = complete anesthesia. | 24hour post nerve block | 
| Motor block of upper limb | A validated 3-point scale was used: 0 = no block (patient has normal power), 1 = patient can feel weakness with the unblocked side, and 2 = complete anesthesia. | 45min post nerve block | 
| Motor block of upper limb | A validated 3-point scale was used: 0 = no block (patient has normal power), 1 = patient can feel weakness with the unblocked side, and 2 = complete anesthesia. | 24hour post nerve block | 
| Motor block of upper limb | A validated 3-point scale was used: 0 = no block (patient has normal power), 1 = patient can feel weakness with the unblocked side, and 2 = complete anesthesia. | 48hour post nerve block |