A Comparison of Ultrasound and Nerve Stimulator Techniques for Nerve Localization in Regional Anesthesia

Study Overview
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Brief Summary
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The primary objective of this study is to compare ultrasound versus nerve stimulator techniques for nerve localization when performing peripheral nerve blocks. Specifically the investigators will be performing Popliteal, Femoral, and Interscalene nerve blocks. The investigators will be looking for differences in 1) time taken to locate the target nerve and inject local anesthetic 2) time from injection of local anesthetic to adequate surgical anesthesia 3) effectiveness of block 4) incidence of vascular puncture 5) incidence of adverse events 6) patient satisfaction.

Detailed Description
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After obtaining informed consent, subjects will be randomized to either the ultrasound or nerve stimulator groups as the method for nerve localization prior to peripheral block placement.

Official Title
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A Comparison of Ultrasound and Nerve Stimulator Techniques for Nerve Localization in Regional Anesthesia

Conditions
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Orthopedic

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: American Society of Anesthesiologists (ASA) Physical status I-III Arthroscopic knee surgery or Lower leg/foot surgery as well as shoulder arthroscopy Outpatient status Patient preference for a regional anesthetic Subjects should be capable of giving informed consent Exclusion Criteria: Allergy to: Local anesthetics Hydromorphone Propofol Midazolam Patient refusal Infection at the injection site Peripheral Neuropathy

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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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Interscalene Ultrasound<br>Subjects having orthopedic surgery requiring an interscalene peripheral nerve block and randomized to have the ultrasound used to locate the nerve. | |
| Interscalene Nerve Stimulator<br>Subjects having orthopedic surgery requiring an interscalene peripheral nerve block and randomized to have the nerve stimulator used to locate the nerve. | |
| Popliteal Ultrasound<br>Subjects having orthopedic surgery requiring an popliteal peripheral nerve block and randomized to have the ultrasound used to locate the nerve. | |
| Popliteal Nerve Stimulator<br>Subjects having orthopedic surgery requiring an popliteal peripheral nerve block and randomized to have the nerve stimulator used to locate the nerve. | |
| Femoral Ultrasound<br>Subjects having orthopedic surgery requiring an femoral peripheral nerve block and randomized to have the ultrasound used to locate the nerve. | |
| Femoral Nerve Stimulator<br>Subjects having orthopedic surgery requiring an femoral peripheral nerve block and randomized to have the nerve stimulator used to locate the nerve. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| time from injection of local anesthetic to adequate surgical anesthesia |  | within the first 45 minutes after injection of local anesthestic | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| effectiveness of block |  | within 1 hour of injection | 
| time taken to locate the target nerve and inject local anesthetic |  | within 45 minutes prior to injection | 
| incidence of vascular puncture |  | within 30 minutes of injection | 
| incidence of adverse events |  | within 2 weeks of the day of surgery | 
| patient satisfaction |  | within 2 weeks of the date of surgery |