Suprascapular Nerve Block as Postoperative Analgesia After Artroscopic Shoulder Surgery

Study Overview
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Brief Summary
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The purpose of this randomized study is to examine the effect of a selective suprascapular nerve block on post operative pain after arthroscopic shoulder surgery. Half of the subjects will receive a active nerve block with Ropivacain. Half of the subjects will receive a placebo nerve block with saline.

Detailed Description
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Postoperative pain management after arthroscopic shoulder surgery traditionally includes opioids and/or an interscalene brachial plexus block(IBPB). Opioid consumption often leads to unpleasant side effects including nausea, vomitting and sedation. IBPB offers very efficient pain relief but includes the discomfort of a paralyzed arm. Furthermore this approach often also leads to unilateral paresis of the phrenic nerve causing reduced respiratory capacity. The latter offering discomfort and a potential risk in patients with lung diseases or heavy overweight. The suprascapular nerve is the most important nerve to the shoulder and a selective block of this nerve could offer a good pain relief without the mentioned side effects. In this randomized study the investigators wish to examine the pain relieving effect of a selective block of the suprascapular nerve after arthroscopic shoulder surgery. 40 patients are randomized to a block of this nerve with either active drug (Ropivacaine) or placebo (Saline). All patients will get a PCA (Patient Controlled Analgesia) pump for administration of i.v. morphine in doses based on age and weight. Patient are being monitored for 6 hours. The primary outcome is reduction in VAS at rest from baseline to 30 minutes after nerve block.

Official Title
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Suprascapular Nerve Block as Postoperative Analgesia After Artroscopic Shoulder Surgery - a Randomized, Blinded, Placebo Controlled Study

Conditions
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Pain

Intervention / Treatment
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* Drug: Ropivacaine hydrochloride
* Drug: Isotonic Saline


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients planned for arthroscopic shoulder surgery. Age ≥ 18. ASA class ≤ 3. Exclusion Criteria: Patients with VAS never ≥5 mm during the first hour after arrivel to the post anesthesia care unit. Patients unable to cooperate. Patients unable to understand or speak danish. Allergy towards the used drugs. Abuse of alcohol- and/or medicine - investigators assessment. Usage of opioids on a daily basis (not including Tramadole). Pregnancy (It is obligatory for all fertile women in the study to take a hcg urine test). Operations involving the clavicle. Operations converted to open surgery.

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: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Ropivacaine hydrochloride<br>Ropivacain 7.5mg/ml, 5 ml injected perineural at the suprascapular nerve. | Drug: Ropivacaine hydrochloride<br>* Ropivacaine injected perineural at the suprascapular nerve.<br>* Other names: Ropivacaine, Naropin;|
| Placebo Comparator: Isotonic Saline<br>0.9% Saline solution, 5 ml injected perineural at the suprascapular nerve. | Drug: Isotonic Saline<br>* Saline injected perineural at the suprascapular nerve.<br>* Other names: Saline;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Visual analogue scale (VAS) score at rest at T½ | Change in VAS score at rest from baseline to 30 minutes after nerve block (T½). | 30 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| VAS score during maximum active shoulder abduction from T½ to T6 | VAS scores measured at 7 timepoints (T½, T1, T2, T3, T4, T5, T6) during maximal active shoulder abduction and calculated as area under the curve (AUC). | 6 hours | 
| VAS score at rest from T½ to T6 | VAS scores measured at 7 timepoints (T½, T1, T2, T3, T4, T5, T6) at rest and calculated as area under the curve (AUC). | 6 hours | 
| Morphine consumption. | The total amount of morphine administered via the intravenous PCA pump the first 6 hours after nerve block. | 6 hours | 
| Electromyography at T½ | Change in activity of the infraspinatus muscle measured with surface electromyography from baseline to T½. | 30 minutes | 
| Muscle strength at T½ | Change in strength of the supraspinatus (abduction of the shoulder) and the infraspinatus muscle (external rotation of the shoulder) measured with a handheld dynamometer from baseline to T½. | 30 minutes | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Peripheral Nerve Blocks