The Effect of Brachial Plexus Nerve Block on Distal Peripheral Nerve Conduction

Study Overview
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Brief Summary
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The purpose of this study is to determine the conducting ability of distal extremity nerves after a supraclavicular brachial plexus nerve block (with local anesthetic) has been placed at a more proximal location in the upper extremity.

Official Title
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The Effect of Brachial Plexus Nerve Block on Distal Peripheral Nerve Conduction

Conditions
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Anesthesia

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male and female military health care beneficiaries 18 years and older, capable of providing informed consent indicating awareness of the investigational nature of the study, in keeping with institutional policy Written informed consent must be obtained from each patient prior to entering the study Patients must be willing to have a regional anesthetic nerve block placed prior to their scheduled procedure Patients must be willing to have neurodiagnostic tests performed prior to placement and after placement of the regional anesthesia nerve block Exclusion Criteria: Refusal to have a brachial plexus nerve block placed Refusal to have serial nerve conduction studies performed Contraindication for a regional anesthesia nerve block (allergy to local anesthetic, infection at site of injection, elevated coagulation time) Presence of conditions affecting the hand or arm (e.g., injury, infection) that might preclude the performance of nerve conduction studies Presence of known major abnormalities of nerve conduction, e.g., absent median sensory potential in a patient scheduled for carpal tunnel release Presence of conditions affecting the contralateral hand or arm (e.g., injury, infection) that might preclude the performance of sensory and motor studies to test block or absence of a contralateral upper extremity

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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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Compund Muscle Action Potential (CMAP) amplitude | measured for motor studies from baseline to peak in mV | 1 day | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Distal Latency | the interval between the stimulation of a compound muscle and the observed response. Normal nerve conduction velocity is above 40 m/sec in the lower extremities and above 50 m/sec in the upper extremities, but age, muscle disease, temperature, and other factors can influence the velocity. | 1 day | 
| Peak Latency | This represents conduction along the majority of the axons It is recorded at the peak of the waveform response | 1 day | 
| Onset Latency | This represents conduction along the fastest axons It is recorded at the initial deflection from baseline | 1 day | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Brachial Plexus, Nerve Block, Nerve Conduction