Interscalene Block Versus Combined Infraclavicular-Anterior Suprascapular Blocks for Shoulder Surgery

Study Overview
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Brief Summary
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Postoperative analgesia after shoulder surgery remains a challenge in patients with preexisting pulmonary pathology, as interscalene brachial plexus block (ISB), the standard nerve block for shoulder surgery, carries a prohibitive risk of hemidiaphragmatic paralysis (HDP). Although several diaphragm-sparing nerve blocks have been proposed, none seems to offer equivalent analgesia to ISB while avoiding HDP altogether. For instance, even costoclavicular blocks, which initially fulfilled both requirements, were subsequently found to result in a non-negligible 5%-incidence of HDP. In this randomized trial, the authors set out to compare ISB and combined infraclavicular block-anterior suprascapular nerve blocks (ICB-ASSNB) for patients undergoing arthroscopic shoulder surgery. The authors hypothesized that ICB-ASSNB would provide equivalent postoperative analgesia to ISB 30 minutes after shoulder surgery and therefore designed the current study as an equivalence trial.

Official Title
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A Randomized Comparison Between Interscalene And Combined Infraclavicular-Anterior Suprascapular Nerve Blocks For Arthroscopic Shoulder Surgery

Conditions
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Pain, Postoperative, Shoulder Pain, Surgical Procedure, Unspecified, Diaphragmatic Paralysis

Intervention / Treatment
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* Procedure: Interscalene Block
* Procedure: Infraclavicular - Anterior Supraescapular Nerve Blocks


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients undergoing arthroscopic shoulder surgery American Society of Anesthesiologists classification 1-3 Body mass index between 20 and 35 kg/mt2 Exclusion Criteria: Adults who are unable to give their own consent Pre-existing neuropathy (assessed by history and physical examination) Coagulopathy (assessed by history and physical examination and, if deemed clinically necessary, by blood work up i.e. platelets ≤ 100, International Normalized Ratio ≥ 1.4 or prothrombin time ≥ 50) Obstructive or restrictive pulmonary disease (assessed by history and physical examination) Renal failure (assessed by history and physical examination and, if deemed clinically necessary, by blood work up i.e. creatinine ≥ 100) Hepatic failure (assessed by history and physical examination and, if deemed clinically necessary, by blood work up i.e. transaminases ≥ 100) Allergy to local anesthetics (LAs) Pregnancy Prior surgery in the neck or infraclavicular region Chronic pain syndromes requiring opioid intake at home

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 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: Supportive Care
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Interscalene Block<br>Patients randomized to receive an interscalene block. | Procedure: Interscalene Block<br>* Ultrasound-guided brachial plexus block injecting 20 ml of bupivacaine 0.5% plus epinephrine 5 micrograms per ml in the Interscalene groove. Patients will receive dexamethasone 4 mg intravenously and an ultrasound-guided intermediate cervical plexus block (5 ml of bupivacaine 0.5% plus epinephrine 5 micrograms per ml).<br>* Other names: Peripheral Nerve Block;|
| Experimental: Infraclavicular-Anterior Supraescapular Nerve Blocks<br>Patients randomized to receive a combined infraclavicular plus anterior suprascapular nerve blocks. | Procedure: Infraclavicular - Anterior Supraescapular Nerve Blocks<br>* Ultrasound-guided combined infraclavicular-anterior suprascapular block of the brachial plexus, injecting 20 ml of bupivacaine 0.5% plus epinephrine 5 micrograms per ml dorsal to the axillary artery in the infraclavicular fossa plus an ultrasound-guided injection of 3 ml of bupivacaine 0.5% plus epinephrine 5 micrograms per ml under the omohyoid muscle. If the anterior suprascapular nerve could not be identified after five minutes of insonation time, an upper trunk block will be carried out with the same amount of local anesthetic. Patients will receive dexamethasone 4 mg intravenously and an ultrasound-guided intermediate cervical plexus block (5 ml of bupivacaine 0.5% plus epinephrine 5 micrograms per ml).<br>* Other names: Peripheral Nerve Block;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Static pain 30 minutes after arrival in the post anesthesia care unit (PACU) | Pain intensity at rest using a numeric rating score (NRS) ranged from 0 to 10 (0 = no pain and 10 = worst imaginable pain) | 30 minutes after PACU arrival | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Static pain 1 hour after arrival in the PACU | Pain intensity at rest using a NRS ranged from 0 to 10 (0 = no pain and 10 = worst imaginable pain) | 1 hour after PACU arrival | 
| Static pain 3 hours after arrival in the PACU | Pain intensity at rest using a NRS ranged from 0 to 10 (0 = no pain and 10 = worst imaginable pain) | 3 hours after PACU arrival | 
| Static pain 6 hours after arrival in the PACU | Pain intensity at rest using a NRS ranged from 0 to 10 (0 = no pain and 10 = worst imaginable pain) | 6 hours after PACU arrival | 
| Static pain 12 hours after arrival in the PACU | Pain intensity at rest using a NRS ranged from 0 to 10 (0 = no pain and 10 = worst imaginable pain) | 12 hours after PACU arrival | 
| Static pain 24 hours after arrival in the PACU | Pain intensity at rest using a NRS ranged from 0 to 10 (0 = no pain and 10 = worst imaginable pain) | 24 hours after PACU arrival | 
| Static pain 36 hours after arrival in the PACU | Pain intensity at rest using a NRS ranged from 0 to 10 (0 = no pain and 10 = worst imaginable pain) | 36 hours after PACU arrival | 
| Static pain 48 hours after arrival in the PACU | Pain intensity at rest using a NRS ranged from 0 to 10 (0 = no pain and 10 = worst imaginable pain) | 48 hours after PACU arrival | 
| Block performance time | Time from skin disinfection until the end of local anesthetic injection | 1 hour before surgery | 
| Intensity of pain during block procedure | Evaluated with the Numeric Rating Scale for Pain. This scale is graduated from 0 to 10 points. A 0-point score represents the absence of pain, and a 10-points score represents the worst imaginable pain. Patients will be asked to rate their pain verbally with this scale. The blinded assessor will register the score reported. | 1 hour before surgery | 
| Incidence of nerve block side effects | Determined by the presence of paresthesia, local anesthetic systemic toxicity, vascular puncture, Horner syndrome, or hoarseness after the block. | 0 minutes after skin disinfection to 30 minutes after the nerve block | 
| Sensory and motor block score | The sensorimotor block will be assessed every 5 minutes until 30 minutes after the end of local anesthetic injection using a 14-point composite score that encompasses the sensory functions of the axillary and supraclavicular nerves as well as the motor functions of the axillary, suprascapular, subscapular and lateral pectoral nerves Sensation will be assessed with ice in each nerve territory with a 0 to 2 point scale. 0= no block, patients can feel cold; 1= analgesic block, the patient can feel touch but not cold; 2= anesthetic block, the patient cannot feel cold or touch. The motor function will be assessed for each nerve with a 0 to 2 points scale where 0= no motor block; 1= paresis; 2= paralysis. Successful blocks at 30 minutes correlate with a final score ( sum of all individual sensory and motor scores) of at least 12 points out of 14, with a sensory score of at least 3 points (out of 4 points). | 30 minutes after the ending time of local anesthetic injection | 
| Block onset time | Time required to reach a minimal sensorimotor composite score of 12 points out of a maximum of 14 points. The sensorimotor score is described in outcome 12. | 1 hour before surgery | 
| Basal diaphragmatic function | Diaphragmatic function evaluated before the nerve block | 1 hour before surgery | 
| Incidence of hemidiaphragmatic paralysis (HDP) at 30 minutes after interscalene or infraclavicular-suprascapular block | HDP will be defined as the absence of diaphragmatic motion during normal respiration coupled with absent or (paradoxical) cranial diaphragmatic movement when the patient forcefully sniffs | 30 minutes after the ending time of local anesthetic injection | 
| Incidence of HDP 30 minutes after PACU arrival | HDP will be defined as the absence of diaphragmatic motion during normal respiration coupled with absent or (paradoxical) cranial diaphragmatic movement when the patient forcefully sniffs | 30 minutes after PACU arrival | 
| Duration of surgery | Time between skin incision and closure (min) | 4 hours after skin incision | 
| Postoperative opioid related side effects | Presence of postoperative nausea, vomiting, pruritus, urinary retention, respiratory depression. | 48 hours after PACU arrival | 
| Intraoperative opioid requirements | Total amount of fentanyl required during general anesthesia | Intraoperative period | 
| Postoperative opioid consumption | Total amount of morphine required during the first 48 hours after surgery | 48 hours after PACU arrival | 
| Patient satisfaction | Patient satisfaction at 24 hours using a 0-10 scale (0 = not satisfied; 10 = very satisfied) | 24 hours after PACU arrival | 
| Persistent neurologic deficit | Presence of persistent sensory or motor postoperative deficit. The patients will be contacted by telephone and inquired about any sensory or motor deficit in the operated extremity. | 7 days after surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Postoperative Shoulder Analgesia, Diaphragmatic Paralysis, Alternative Blocks