The Effects of Different Clonidine Concentrations on Axillary Brachial Plexus Block With 1,5% Lidocaine

Study Overview
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Brief Summary
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The purpose of this study is to determine whether different clonidine concentration on axillary brachial plexus block with 1,5% lidocaine for upper limb surgery may influence the sensory and motor block onset time and duration, postoperative analgesia duration, postoperative pain intensity

Detailed Description
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Brachial plexus blocks are frequently used in surgical procedures involving the upper limb because they facilitate surgical anaesthesia, muscle relaxation and post-operative analgesics. Various drugs are used to supplement local anaesthetics during brachial plexus block. Many studies in the literature show that clonidine, which is an alpha-2 agonist, prolongs the length of anesthesia and post-operative analgesia.4,5 However, clonidine's side effects-such as hypotension, bradycardia and sedation can limit its use. There are no studies comparing different clonidine concentrations on the axillary brachial block, so the hypothesis of the present study was that different clonidine concentrations and LA volumes may influence the anaesthesia and analgesia quality on this type of regional block.

Official Title
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The Effects of Different Clonidine Concentrations on Axillary Brachial Plexus Block With 1,5% Lidocaine for Upper Limb Surgery: a Prospective Randomized Study

Conditions
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Fascicular Block, Motor Activity, Pain, Postoperative, Latency Period

Intervention / Treatment
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* Drug: high Clonidine concentration
* Drug: low clonidine concentration
* Drug: Lidocaine
* Drug: Lidocaine 40 ml


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: both genders, over 18 years old, American Society of Anesthesiologists (ASA) 1 to 3 Exclusion Criteria: patients with chronic use of analgesics and non-steroidal anti-inflammatories drugs, pregnant, with infection at the puncture site, coagulopathies or intolerance to drugs used in the study

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 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: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: low clonidine concentration<br>clonidine concentration 1 ml on 40 ml of lidocaine 1.5% for upper brachial plexus | Drug: low clonidine concentration<br>* Clonidine 1 ml - 150 mcg on 40 ml of lidocaine 1,5% - single injection on axillary brachial plexus block for upper limb<br>|
| Active Comparator: lidocaine 20 ml 1,5%<br>lidocaine 20 ml 1,5% without clonidine for axillary brachial plexus block for upper limb surgery | Drug: Lidocaine<br>* Lidocaine 1,5% 20 ml 300 mg for single injection on axillary brachial plexus block for upper lim surgery<br>|
| Active Comparator: high clonidine concentration<br>clonidine concentration 150 mcg on 20 ml of lidocaine 1,5% for upper brachial plexus | Drug: high Clonidine concentration<br>* Clonidine 1 ml - 150 mcg on 20 ml de lidocaine 1,5% on axillary brachial plexus block for upper limb surgery<br>|
| Active Comparator: 40 ml lidocaine 1,5%<br>40 ml of lidocaine 1,5% without clonidine for upper brachial plexus | Drug: Lidocaine 40 ml<br>* Lidocaine 40 ml 1,5% 600 mg single injection for axillary brachial plexus block for upper limb surgery<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| sensorial and motor block duration | to compare two concentrations of clonidine on different volumes of lidocaine, in terms of sensorial and motor block duration | 24 hours after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| adverse effects of additive clonidine on axillary brachial plexus block in upper limb surgery | analyse the adverse effects of additive clonidine on axillary brachial plexus block in upper limb surgery | 24 hours after surgery | 
| postoperative analgesia duration | to compare two concentrations of clonidine on different volumes of lidocaine, in terms of postoperative analgesia duration | 24 hours | 
| sensorial and motor block onset time | to compare two concentrations of clonidine on different volumes of lidocaine, in terms of sensorial and motor block onset time | 24 hours | 
| postoperative pain intensity | to compare two concentrations of clonidine on different volumes of lidocaine, in terms postoperative pain intensity | 24 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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brachial plexus, lidocaine, alfa 2 adrenergic receptor clonidine, orthopedic procedure