Brachial Plexus BlockadeNCT07338916
Dose-Finding Study: MEV90 for Local Anesthetic in Interscalene Block for Supraclavicular Nerves Block
A study testing Ultrasound-Guided Interscalene Block with Bupivacaine in people with Brachial Plexus Blockade and Shoulder Surgery, run by Hospital del Trabajador de Santiago at 1 site in Chile.
Trial summary
This study aims to determine the minimum effective volume (MEV90) of local anesthetic required to achieve sensory block of the supraclavicular nerves when performing a single-shot ultrasound-guided interscalene brachial plexus block (ISB). Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Brachial Plexus Blockade, Shoulder Surgery, Superficial Cervical Plexus Block
- What is being tested?
- Ultrasound-Guided Interscalene Block with Bupivacaine
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 57 participants
- Where
- 1 siteChile
- Study dates
- 6 Apr 2026to 1 Oct 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age ≥ 18 years
- ASA physical status I to III
- Body Mass Index (BMI) between 18 and 35 kg/m²
- Weight ≥ 50 kg
- Scheduled for shoulder arthroscopy requiring an interscalene brachial plexus block for analgesia
- Able to provide informed consent
Who cannot join
- Inability to provide informed consent
- Coagulopathy (platelet count ≤100,000; INR ≥1.4)
- Significant pulmonary disease (restrictive or obstructive)
- Renal insufficiency (creatinine ≥1.2 mg/dL)
- Hepatic insufficiency (transaminases ≥100 U/L)
- Allergy to local anesthetics
Show all 10Show fewer
- Pregnancy
- Pre-existing neuropathy
- Previous surgery in ipsilateral cervical or supraclavicular region
- Contralateral hemidiaphragmatic paralysis or vocal cord paralysis
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Minimum Effective Volume (MEV90) of Local Anesthetic Required for Ultrasound-Guided Interscalene Block for Supraclavicular Nerve Block: A Dose-Finding Study
This study aims to determine the minimum effective volume (MEV90) of local anesthetic required to achieve sensory block of the supraclavicular nerves when performing a single-shot ultrasound-guided interscalene brachial plexus block (ISB). These nerves provide sensation to the skin over the clavicle and shoulder and are often involved in surgeries such as shoulder arthroscopy and clavicle repair.
Read the detailed description
This prospective dose-finding study seeks to determine the minimum effective volume (MEV90) of local anesthetic required to achieve sensory block of the supraclavicular nerves following a single-shot ultrasound-guided interscalene brachial plexus block (ISB). These nerves, branches of the superficial cervical plexus, provide cutaneous innervation over the clavicle and shoulder and may contribute to postoperative pain after shoulder and clavicular surgery. Establishing MEV90 is clinically relevant to optimize analgesia while minimizing the risk of local anesthetic systemic toxicity.
The study employs a biased coin up-and-down sequential design, commonly used in regional anesthesia dose-finding trials. The initial volume is 12 mL of bupivacaine 0.5% with epinephrine (5 µg/mL), with subsequent volumes adjusted in 2 mL increments based on the prior patient's response. The maximum permitted volume is 30 mL.
All blocks are performed under ultrasound guidance by experienced anesthesiologists (≥60 ISBs), following standard safety protocols.
This intervention does not introduce additional risk beyond routine care, as ISB is the gold standard for shoulder surgery analgesia. Results will inform whether a single interscalene injection provides adequate coverage of supraclavicular nerves or if a separate cervical plexus block is necessary for procedures involving both plexuses, such as clavicle surgery. Findings may refine volume recommendations, improve analgesic strategies, and reduce unnecessary drug exposure.
- Being tested
- Ultrasound-Guided Interscalene Block with Bupivacaine
- Keywords
- Interscalene Block, Brachial Plexus Blockade, Supraclavicular nerves block, Shoulder Surgery, Miminum Effective Volume 90, MEV90
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Ultrasound-Guided Interscalene Block with BupivacaineDrug
Participants will receive a single-shot interscalene brachial plexus block performed under real-time ultrasound guidance. The block targets the C5-C6 nerve roots between the anterior and middle scalene muscles using an in-plane technique. The local anesthetic is bupivacaine 0.5% with epinephrine (5 µg/mL). The injected volume ranges from 12 mL to 30 mL, determined by a dose-finding algorithm (biased coin up-and-down sequential design) to calculate the minimum effective volume (MEV90) for supraclavicular nerve block. All procedures are performed by experienced anesthesiologists following standard safety protocols, including incremental injection with aspiration and continuous monitoring (ECG, SpO₂, non-invasive blood pressure).
| Study group | Role | What they receive |
|---|---|---|
| Minimum Effective Volume 90 (MEV90) | Experimental | Participants in this arm will receive a single-shot ultrasound-guided interscalene brachial plexus block as part of standard perioperative analgesia for shoulder arthroscopy. The intervention consists of injecting bupivacaine 0.5% with epinephrine (5 µg/mL) between the anterior and middle scalene muscles at the level of the C5-C6 nerve roots, using an in-plane technique under real-time ultrasound guidance. Receives: Drug: Ultrasound-Guided Interscalene Block with Bupivacaine |
What is being measured
The primary outcome is the main question the study is designed to answer.
Minimum Effective Volume (MEV90) for Supraclavicular Nerve Block via Interscalene Approach
The primary outcome is the calculation of the minimum effective volume of local anesthetic (MEV90) required to achieve complete sensory block of the supraclavicular nerves following a single-shot ultrasound-guided interscalene brachial plexus block. Success is defined as absence of cold and touch sensation at the midpoint of the clavicle, assessed using an ice test.
Measured: 30 minutes after completion of the block
Secondary outcomes (7)
Sensorimotor Block Score for Interscalene Block
Composite score (0-8 points) assessing sensory and motor block in C5-C6 dermatomes using ice test and motor function (shoulder abduction and external rotation). Success defined as ≥6 points.
Measured: Every 5 minutes up to 30 minutes after block completion.
Onset Time of Sensorimotor Block
Interval (minutes) between completion of local anesthetic injection and achievement of ≥6 points on the sensorimotor scale.
Measured: Up to 30 minutes after block completion.
Sensory Block at Shoulder Arthroscopy Portals
Presence or absence of cold and touch sensation at anterior, lateral, and posterior portal sites using ice test.
Measured: 30 minutes after block completion.
Sensory Block of Auricular, Occipital, and Transverse Cervical Nerves
Assessment of sensory block in territories of auricular major, occipital minor, and transverse cervical nerves using ice test.
Measured: 30 minutes after block completion.
Pain Score During Block Procedure
Patient-reported pain during needle insertion and injection, measured using Visual Analog Scale (VAS, 0-10).
Measured: Immediately after block completion.
Block Performance Times
Time intervals for image acquisition, needle placement, and total block execution (minutes).
Measured: During block procedure.
Incidence of Block-Related Adverse Events
Occurrence of complications including Horner's syndrome, hoarseness, dyspnea, vascular puncture, hematoma, paresthesia, and symptoms of local anesthetic systemic toxicity (LAST).
Measured: From block completion until end of surgery.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted14 Jan 2026
- Study start6 Apr 2026
- Primary completion1 Oct 2026
- Study completion1 Oct 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Brachial Plexus BlockadeStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Supportive care
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 57 participants (actual)
Sponsor and investigators
- Lead sponsor
- Hospital del Trabajador de Santiago
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Germán Armando Aguilera Ceballos, Hospital del Trabajador de Santiago
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07338916
- Sponsor's protocol ID
- Project Nº34, 2025
- Other IDs
- 251213001
- Status last verified
- Oct 2026
- First submitted
- 4 Jan 2026
- Last updated
- 6 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 6 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Minimum Effective Volume (MEV90) of Local Anesthetic Required for Ultrasound-Guided Interscalene Block for Supraclavicular Nerve Block: A Dose-Finding Study
- ClinicalTrials.gov ID
- NCT07338916
- Acronym / sponsor ID
- Project Nº34, 2025
- Keywords
- Interscalene Block, Brachial Plexus Blockade, Supraclavicular nerves block, Shoulder Surgery, Miminum Effective Volume 90, MEV90
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 57 participants (actual)
- Lead sponsor
- Hospital del Trabajador de SantiagoUniversity, hospital or other
- Study start
- 6 Apr 2026 (actual)
- Primary completion
- 1 Oct 2026 (actual)
- Study completion
- 1 Oct 2026 (actual)
- First posted
- 14 Jan 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study aims to determine the minimum effective volume (MEV90) of local anesthetic required to achieve sensory block of the supraclavicular nerves when performing a single-shot ultrasound-guided interscalene brachial plexus block (ISB). These nerves provide sensation to the skin over the clavicle and shoulder and are often involved in surgeries such as shoulder arthroscopy and clavicle repair.
Detailed description
This prospective dose-finding study seeks to determine the minimum effective volume (MEV90) of local anesthetic required to achieve sensory block of the supraclavicular nerves following a single-shot ultrasound-guided interscalene brachial plexus block (ISB). These nerves, branches of the superficial cervical plexus, provide cutaneous innervation over the clavicle and shoulder and may contribute to postoperative pain after shoulder and clavicular surgery. Establishing MEV90 is clinically relevant to optimize analgesia while minimizing the risk of local anesthetic systemic toxicity.
The study employs a biased coin up-and-down sequential design, commonly used in regional anesthesia dose-finding trials. The initial volume is 12 mL of bupivacaine 0.5% with epinephrine (5 µg/mL), with subsequent volumes adjusted in 2 mL increments based on the prior patient's response. The maximum permitted volume is 30 mL.
All blocks are performed under ultrasound guidance by experienced anesthesiologists (≥60 ISBs), following standard safety protocols.
This intervention does not introduce additional risk beyond routine care, as ISB is the gold standard for shoulder surgery analgesia. Results will inform whether a single interscalene injection provides adequate coverage of supraclavicular nerves or if a separate cervical plexus block is necessary for procedures involving both plexuses, such as clavicle surgery. Findings may refine volume recommendations, improve analgesic strategies, and reduce unnecessary drug exposure.
Study design
- Primary purpose
- Supportive care
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Minimum Effective Volume 90 (MEV90) | Experimental | Drug: Ultrasound-Guided Interscalene Block with BupivacaineParticipants in this arm will receive a single-shot ultrasound-guided interscalene brachial plexus block as part of standard perioperative analgesia for shoulder arthroscopy. The intervention consists of injecting bupivacaine 0.5% with epinephrine (5 µg/mL) between the anterior and middle scalene muscles at the level of the C5-C6 nerve roots, using an in-plane technique under real-time ultrasound guidance. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Age ≥ 18 years
- ASA physical status I to III
- Body Mass Index (BMI) between 18 and 35 kg/m²
- Weight ≥ 50 kg
- Scheduled for shoulder arthroscopy requiring an interscalene brachial plexus block for analgesia
Key exclusion criteria (10 listed)
- Inability to provide informed consent
- Coagulopathy (platelet count ≤100,000; INR ≥1.4)
- Significant pulmonary disease (restrictive or obstructive)
- Renal insufficiency (creatinine ≥1.2 mg/dL)
- Hepatic insufficiency (transaminases ≥100 U/L)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Ultrasound-Guided Interscalene Block with BupivacaineParticipants will receive a single-shot interscalene brachial plexus block performed under real-time ultrasound guidance. The block targets the C5-C6 nerve roots between the anterior and middle scalene muscles using an in-plane technique. The local anesthetic is bupivacaine 0.5% with epinephrine (5 µg/mL). The injected volume ranges from 12 mL to 30 mL, determined by a dose-finding algorithm (biased coin up-and-down sequential design) to calculate the minimum effective volume (MEV90) for supraclavicular nerve block. All procedures are performed by experienced anesthesiologists following standard safety protocols, including incremental injection with aspiration and continuous monitoring (ECG, SpO₂, non-invasive blood pressure). | Drug | Minimum Effective Volume 90 (MEV90) |
Primary outcome
Minimum Effective Volume (MEV90) for Supraclavicular Nerve Block via Interscalene Approach
Time frame: 30 minutes after completion of the block
The primary outcome is the calculation of the minimum effective volume of local anesthetic (MEV90) required to achieve complete sensory block of the supraclavicular nerves following a single-shot ultrasound-guided interscalene brachial plexus block. Success is defined as absence of cold and touch sensation at the midpoint of the clavicle, assessed using an ice test.
7 secondary outcomes
Sensorimotor Block Score for Interscalene Block
Time frame: Every 5 minutes up to 30 minutes after block completion.
Onset Time of Sensorimotor Block
Time frame: Up to 30 minutes after block completion.
Sensory Block at Shoulder Arthroscopy Portals
Time frame: 30 minutes after block completion.
Sensory Block of Auricular, Occipital, and Transverse Cervical Nerves
Time frame: 30 minutes after block completion.
Pain Score During Block Procedure
Time frame: Immediately after block completion.
Block Performance Times
Time frame: During block procedure.
Incidence of Block-Related Adverse Events
Time frame: From block completion until end of surgery.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 6 Oct 2026.
- Individual participant dataSharing planned: No
Related trials for Brachial Plexus Blockade
RecruitingObservational study
Pulse Wave Transit Time After Infraclavicular Block
Infraclavicular Brachial Plexus Block
RecruitingObservational study
Evaluating Hemidiaphragmatic Paralysis With Prolonged Neural Blockade From an Interscalene Brachial Plexus Block
Shoulder Surgery, Shoulder Pain
Not yet recruitingObservational study
Body Mass Index and Outcomes of Ultrasound-Guided Infraclavicular Brachial Plexus Block
Obesity (BMI>30)
Not yet recruiting
Combined Suprascapular and PECS I Blocks Versus Interscalene Block for Shoulder Arthroscopy
Postoperative Pain, Hemidiaphragmatic Paresis
RecruitingPhase 4
Intravenous Dexamethasone With Single-Shot Versus Continuous Brachial Plexus Block for Rebound Pain After Shoulder Surgery
Pain, Postoperative, Rebound Pain
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Ultrasound-Guided Interscalene Block with Bupivacaine in people with Brachial Plexus Blockade and Shoulder Surgery, run by Hospital del Trabajador de Santiago at 1 site in Chile.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 6 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Chile. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Minimum Effective Volume (MEV90) for Supraclavicular Nerve Block via Interscalene Approach (time frame: 30 minutes after completion of the block). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 6 Oct 2026.