Respiratory Impact of LA Volume After IS Block

Study Overview
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Brief Summary
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The hypothesis of this study is that a reduced extrafascial volume of local anesthetic for an interscalene brachial plexus block is associated with a lower incidence of diaphragmatic hemiparalysis after an arthroscopic surgery of the shoulder, without any reduction of the analgesic efficacy.

Detailed Description
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The hypothesis of this study is that a reduced extrafascial volume of local anesthetic for an interscalene brachial plexus block is associated with a lower incidence of diaphragmatic hemiparalysis after an arthroscopic surgery of the shoulder, without any reduction of the analgesic efficacy. Our prospective randomized controlled trial will include two parallel groups: a group will receive a volume of 20 mls of ropivacaine 0.75%, while the other group will receive a volume of 10 mls. All participants will have a preoperative ultrasound-guided interscalene brachial plexus with an extrafascial injection of 10 or 20 mls of ropivacaine 0.75%. In both groups, participants will have an examination of the hemidiaphgragm with the ultrasound, before and 30 min after the block. The respiratory function will also be assessed with a bedside spirometer before and after the block, and at 12 and 24 postoperative hours. During surgery all participants will receive multimodal analgesia inclusive of iv dexamethasone 8 mg, iv magnesium sulfate 40 milligram kg^2, iv ketorolac 30 milligrams, and iv acetaminophen 1000 milligrams, according to the current practice in our institution. In the postoperative period, Participants will be prescribed an IV pca of morphine. Assignment to one of these two groups will be done according to a computer-generated list of random numbers, and the sealed envelopes method will be used.

Official Title
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Respiratory Impact of Local Anaesthetic Volume for an Interscalene Brachial Plexus Block With an Extrafascial Approach.

Conditions
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Arthroscopic Surgery of the Shoulder, Extrafascial Interscalene Plexus Brachial Block

Intervention / Treatment
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* Drug: Ropivacaine 0.75% Injectable Solution
* Drug: Ropivacaine 0.75% Injectable Solution


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: arthroscopic surgery of the shoulder ASA class 1 to 3 age more than 18 years old Exclusion Criteria: patient refusal or inability to understand and/or sign the inform consent contraindication for perineural block (allergy to local anesthetics, infection of puncture site, major coagulopathy, sensitive or motor deficiency on the operative side arm chronic alcool abuse opioid drug abuse or under substitution treatment patients known for allergies to paracetamol, non steroidal anti inflammatory drugs, dexamethasone, sulfate magnesium, ondansetron, droperidol, and omeprazole; patients under chronic corticotherapy patients known for malignant hyperthermia; patients with chronic kidney failure (Glomerular Filtration Rate < 20 ml/min) patients with severe pulmonary disease patients with history of neck surgery or radiotherapy on the operative side; pregnancy

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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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 10 ml single-shot injection<br>In the 10ml group, participants will have an interscalene brachial plexus with an extrafascial injection of 10 ml ropivacaine 0.75% at the level of C5-C6 nerves roots. Participants will also receive multimodal analgesia with injection of dexamethasone 8 mg iv, magnesium sulfate 40 mg kg^-1 iv, ketorolac 30 mg iv, and acetaminophen 1000 mg iv, according to the current practice in our institution. | Drug: Ropivacaine 0.75% Injectable Solution<br>* 10 ml extrafascial interscalene brachial plexus block<br>|
| Active Comparator: 20 ml single-shot injection group<br>In the 20ml group, participants will have an interscalene brachial plexus with an extrafascial injection of 20 ml ropivacaine 0.75% at the level of C5-C6 nerves roots. Participants will also receive multimodal analgesia with injection of dexamethasone 8 mg iv, magnesium sulfate 40 mg kg^-1 iv, ketorolac 30 mg iv, and acetaminophen 1000 mg iv, according to the current practice in our institution. | Drug: Ropivacaine 0.75% Injectable Solution<br>* 20 ml extrafascial interscalene brachial plexus block<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of hemidiaphragmatic paralysis |  | 30 minutes after the interscalene plexus brachial extrafascial injection | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of hemidiaphragmatic paralysis |  | at 2 and 24 postoperative hours | 
| Presence of Dyspnea | Verbal question to the patient if he has dyspnea or not | in phase 1 recovery and at 12 and 24 postoperative | 
| Presence of PONV | Verbal question to the patient if he has dyspnea or not | in phase 1 recovery and at 12 and 24 postoperative | 
| Presence of Pruritus | Verbal question to the patient if he has pruritus or not | in phase 1 recovery and at 12 and 24 postoperative hours | 
| Presence of Claude-Bernard-Horner syndrome | Examination of the patient | in phase 1 recovery and at 12 and 24 postoperative hours | 
| Presence of Dysphonia | Verbal question to the patient if he has dysphonia or not | in phase 1 recovery and at 12 and 24 postoperative hours | 
| Forced expiratory volume in one second | in liters per second | 30 minutes after the interscalene plexus brachial extrafascial injection, and at 2, 12 and 24 postoperative hours | 
| Forced vital capacity | in liters | 30 minutes after the interscalene plexus brachial extrafascial injection, and at 2, 12 and 24 postoperative hours | 
| Peak expiratory flow | in liters per second | 30 minutes after the interscalene plexus brachial extrafascial injection, and at 2, 12 and 24 postoperative hours | 
| Installation time of sensory block | in minutes | up to 30 minutes after the interscalene plexus brachial extrafascial injection | 
| Installation time of motor block | in minutes | up to 30 minutes after the interscalene plexus brachial extrafascial injection | 
| Time to first dose of postoperative iv morphine | in hours | up to 24 hours postsurgery | 
| Pain scores at rest | Numeric pain intensity scale. Pain scores range from zero (no pain) to 10 (worst possible pain) | in phase 1 recovery and at 12 and 24 postoperative hours | 
| Pain scores on movement | Numeric pain intensity scale. Pain scores range from zero (no pain) to 10 (worst possible pain). | in phase 1 recovery and at 12 and 24 postoperative hours | 
| Cumulative postoperative iv morphine consumption | in milligrams | in phase 1 recovery and at 12 and 24 postoperative hours | 
| Duration of analgesic block | in minutes | up to 24 hours postsurgery | 
| Duration of motor block | in minutes | up to 24 hours postsurgery | 
| Duration of sensory block | in minutes | up to 24 hours postsurgery | 
| Satisfaction of the participants | Numeric satisfaction intensity scale. Satisfactions range from 0 (totally unsatisfied) to 10 (maximal satisfaction). | at 24 postoperative hours |