Comparison of the Analgesic Effect of Different Local Anesthetics in Interscalene Nerve Block for Shoulder Surgery

Study Overview
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Brief Summary
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Several reports have compared the duration of action of levobupivacaine and ropivacaine as local anesthetic. The most widely used method for sensory function evaluation is though means of a pinprick test. The investigators want to use the novel method of Quantitative Sensory Testing to better evaluate the anesthetic activity. This method used hot and cold sensation to assess small nerve fiber function. The investigators will assess the duration of action of different drugs when used in an inter scalene nerve block in patients scheduled for shoulder surgery.

Detailed Description
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This study aims to compare the length of the analgesic effect of different local anesthesic solutions, used in an interscalene nerve block. This will be objectified by measuring the changes in small nerve functioning, using quantative sensory testing. Based on the results of a previous study, the investigators reduce the dose of the administered local anesthetic, expecting a similar length of action using these smaller doses.

Official Title
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Comparison of the Analgesic Effect of the Local Anesthetics Ropicacaine, Levobupivacaine, and Levobupivacaine + Epinephrin Via Interscalene Nerve Block in Patients Undergoing Shoulder Arthroscopy Under General Anesthesia

Conditions
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Other Peripheral Nerve Disease

Intervention / Treatment
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* Drug: Ropivacaine 0.75%
* Drug: Levobupivacaine 0.5%
* Drug: Levobupivacaine 0.5% + epinephrin 1/200000


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: American Society of Anesthesia class I or II Scheduled for shoulder surgery Exclusion Criteria: Mental retardation Allergy for local anesthetics NSAID intolerance or contraindicated Diabetes mellitus Chronic use of pain killers

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 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: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Ropivacaine 0.75%<br>The investigators administer 5 milliliters of Ropivacaine 0.75% in the inter scalene space | Drug: Ropivacaine 0.75%<br>* The investigators adminster 5ml of Ropivacaine 0.75% in an ultrasound-guided inter scalene nerve block<br>* Other names: Naropin;|
| Active Comparator: Levobupivacaine 0.5%<br>The investigators administer 5ml of Levobupivacaine 0.5% in the inter scalene space | Drug: Levobupivacaine 0.5%<br>* The investigators adminster 5ml of Levobupivacaine 0.5% in an ultrasound-guided inter scalene nerve block<br>* Other names: Chirocaine;|
| Active Comparator: Levobupivacaine 0.5% + epinephrin<br>The investigators administer 5ml of Levobupivacaine 0.5% + epinephrin 1/200000 in the inter scalene space | Drug: Levobupivacaine 0.5% + epinephrin 1/200000<br>* The investigators adminster 5ml of Levobupivacaine 0.5% + epinephrin 1/200000 in an ultrasound-guided inter scalene nerve block<br>* Other names: Chirocaine;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Length of nerve block measured in longitudinally recorded significant changes in sensory thresholds using quantitative sensory testing | Length of difference in cold and heat pain and sensation measured with quantitative sensory testing | 24 hours after intervention | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Need for rescue drugs, as requested by the patient after surgery |  | 24 hours after intervention | 
| Motor activity block, longitudinally recorded inability to move the blocked limb |  | 24 hours after intervention | 
| Intensity of nerve block, recorded as maximal changes in sensory thresholds using quantitative sensory testing | The difference in threshold of cold and heat pain and sensation measured with quantitative sensory testing | 24 hours after intervention | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Peripheral nerve block