Effectiveness Study of Different Local Anesthetic Mixtures

Study Overview
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Brief Summary
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Purpose and Background The purpose of this research study is to investigate the benefits of mixing lidocaine and bupivacaine for numbing the skin. Lidocaine and bupivacaine are two commonly used medications to numb the skin for minor procedures. Lidocaine has a faster onset. Bupivacaine has a longer duration. They are often combined with epinephrine to increase the length of action. These medications are used to control pain at the time of the operation and to decrease discomfort immediately afterward. Participating in the study involves injection of local anesthetic containing lidocaine, bupivacaine, and lidocaine and bupivacain with epinephrine at 4 sites on the forearm. Your participation will potentially improve the administration of these medications in persons undergoing a variety of procedures. You will be one of approximately 25 healthy volunteer subjects in this research study.

Detailed Description
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Procedures During your participation the following procedures will be completed: You will be asked to read over and sign this consent form, if you choose to participate You will be asked demographic information and your medical history will be obtained If you are eligible to participate, the palm side of your forearm will be marked for the location of the treatments Four small injections will be made into the palm side of your forearms with the local anesthetic mixtures (you will not know which injection is used at each of the four injection sites) A small needle will be used for pinprick sensation to determine when numbness begins and ends Length of Study and Number of Visits This study begins at the time the medications are injected and is completed when sensation has completely returned. The study will last between 6 and 12 hours. During this time, you may perform low intensity tasks including reading, typing, and writing. You must remain in the study location as the sites will frequently be examined. Exclusions You should not participate in this study if any of the following apply to you: You are pregnant You have an allergy to lidocaine or bupivacaine You have a history of heart disease (including a prior heart attack, heart dysfunction, or heart failure) There may be other criteria that you have to meet to be eligible for this study. The study team can discuss these with you to determine whether you qualify. Discomfort and Risks Risks associated with the injections include temporary discomfort at the injection site and possible infection. It is also possible that you have an allergic reaction or side effect to the medications that are being used. Benefits There is no direct benefit to you for participating in this study. Your participation will potentially improve the administration of these medications in persons undergoing a variety of procedures.

Official Title
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Onset and Duration of Effect of Lidocaine, Bupivacaine, and Lidocaine/Bupivacaine Mixture With Epinephrine.

Conditions
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Pain

Intervention / Treatment
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* Drug: 1% Lidocaine with Epinephrine (1:100,000)
* Drug: 0.25% Bupivacaine with Epinephrine (1:200,000)
* Drug: 0.5% Lidocaine, 0.125 Bupivacaine, and epi (1:150,000)
* Drug: 1% Lidocaine, 0.5% Bupivacaine, and epinephrine (1:150,000)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age: 18-60 Exclusion Criteria: Pregnancy allergy to local anesthetics history of heart disease or diabetes

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 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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Design Details

Primary Purpose: Basic Science
Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Lidocaine w/ Epi<br>0.2ml 1% Lidocaine with Epinephrine (1:100,000) | Drug: 1% Lidocaine with Epinephrine (1:100,000)<br>* 0.2ml Intradermal injection once.<br>|
| Experimental: Bupivacaine with epi<br>0.2 ml 0.25% Bupivacaine with epinephrine (1:200,000) | Drug: 0.25% Bupivacaine with Epinephrine (1:200,000)<br>* 0.2ml Intradermal injection once.<br>|
| Experimental: Low dose Lido and Bupi w/ Epi<br>0.2ml 0.5% Lidocaine + 0.125% Bupivacaine with Epinephrine (1:150,000) | Drug: 0.5% Lidocaine, 0.125 Bupivacaine, and epi (1:150,000)<br>* 0.2ml Intradermal injection once.<br>|
| Experimental: High Dose Lido and Bupi with epi<br>0.2ml 1% Lidocaine + 0.25% Bupivacaine with Epinephrine (1:150,000) | Drug: 1% Lidocaine, 0.5% Bupivacaine, and epinephrine (1:150,000)<br>* 0.2ml Intradermal injection once.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Length of Action | The time from onset of local anesthesia until cessation of effect by sensation of sharp measured in 15 minute increments. | Up to 12 hours | 
| Onset of Action | Time from infusion of local anesthetic to loss of sensation to sharp. | Up to 5 minutes |