Distribution Circumferential Versus Non Circumferential of Mepivacaine in the Median and Ulnar Nerves

Study Overview
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Brief Summary
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Evaluation of the efficacy of the circumferential versus non circumferential distribution of mepivacaine around the median and ulnar nerves. Evaluation the onset of action of mepivacaine in circumferential versus non circumferential distribution around the median and ulnar nerves. Spread of mepivacaine after injection guided by ultrasonography. Complications of both anesthetic techniques in postoperative time.

Official Title
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Circumferential Versus Not Circumferential Distribution of Mepivacaine Around the Median and Ulnar Nerves in the Carpal Tunnel Surgery. Randomized Clinical Trial, Double Blinded.

Conditions
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Anesthesia

Intervention / Treatment
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* Procedure: Circumferential spread of the mepivacaine ultrasonographic guided around the median and ulnar nerves at the elbow
* Procedure: Non circumferential spread in ultrasound-guided median and ulnar nerves block


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Scheduled patients for surgery of carpal tunnel including patients in ASA I-III status, without exclusion criteria. The principal investigator study and/or other designated site staff will obtain written informed consent from all research patients. Exclusion Criteria: Abnormal bleeding, infection in the punction side, allergy or other problems with the medication of the study, muscular or nerve diseases, patients < 18 years old, pregnancy, cognitive disease or reject of the patient

Ages Eligible for Study
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Minimum Age: 18 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: Single Group Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Circumferential (C)<br>Circumferential(C) spread group will be defined as mepivacaine injectate visualized by ultrasonography all around the median and ulnar nerves imaged in short axis. | Procedure: Circumferential spread of the mepivacaine ultrasonographic guided around the median and ulnar nerves at the elbow<br>* Homogeneous spread of 6 ml of mepivacaine 1% around the median and ulnar nerves in each one using several needle passes and active hydrodissection<br>* Other names: Doughnut sign;|
| Other: Non circumferential (NC)<br>Local anesthetic spread will be asymmetrical around the median and ulnar nerves, the mepivacaine will be partially in contact with the nerve | Procedure: Non circumferential spread in ultrasound-guided median and ulnar nerves block<br>* Asymmetric spread of 6 ml of mepivacaine 1% in contact with median and ulnar nerves block in each one, using only one needle pass<br>* Other names: Asymmetric local anesthetic spread;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Efficacy and onset of action | Sensory block will be assessed as a loss of cold sensation elicited by a cold wet cotton swab in the areas of the medial and ulnar nerves by comparison with contralateral hand. Sensory block will be clasiffied as follows: 0, anesthesia; 1, hyposthesia; 2, normal sensation. Motor function will be tested as according to a modified Bromage score: 0, no motor blokade; 1, weak response against resistence; 2, complete motor blockade. Motor and sensory blockades will be assessed by a blinded observer at 5, 15, 30 mins after local anesthetic injection and on arrival in the recovery room. | On arrival in the recovery room | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Complications in postoperative time | Since the nerve block to the hospital outcome will be registered potencial block-related complications. At the first postoperative day, each patient will be called by phone, to report the time at first onset of pain in the operative site and lack of residual postoperative neurologic symptoms, postoperative nausea and vomiting, and hospital readmission (for severity of pain or bleeding or other reasons) | 24 hours postoperative time | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Ultrasonography, Block nerve, Anaesthesia, Carpal tunnel syndrome