Regional Anesthesia MorbidityPhase 1NCT06005480
Understanding Rebound Pain After Regional Anesthesia Resolution in Healthy Volunteers
A Phase 1 study testing Mepivacaine in people with Regional Anesthesia Morbidity and Pain, Acute, run by Brigham and Women's Hospital at 1 site in United States.
Trial summary
Regional anesthesia decreases postoperative pain scores and opioid consumption, and may prevent chronic pain after surgery in patients undergoing surgery. However, some patients experience an increase of pain into the severe range when the nerve block wears off, also known as rebound pain. Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Regional Anesthesia Morbidity, Pain, Acute, Healthy
- What is being tested?
- Mepivacaine
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 40 participants
- Where
- 1 siteUnited States
- Study dates
- 28 Sep 2023to 28 May 2024
- Phase
- Phase 1
- 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 to 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Age ≥ 18 years old, ≤ 65 years old
- BMI >18, < 35
- Able to speak and understand English
- Willingness to undergo psychophysical testing (e.g., QST, pain questionnaires)
- Willingness to have nerve block performed
Who cannot join
- Ongoing acute or chronic pain in upper extremities
- Skin or tissue infection affecting upper extremities
- Previous hypersensitivity to mepivacaine or lidocaine
- Previous neuropathy (numbness, paresthesia, or motor weakness) in either upper extremity
- Loss of any limb
- Bleeding issues or bleeding disorder
Show all 9Show fewer
- History of alcohol or drug abuse
- Currently pregnant or breastfeeding
- History of seizure or epilepsy
Trial locations and contacts
1 site in 1 country.
United States1 site
Brigham and Women's Hospital
Boston, Massachusetts, 02115
About this study
Official title: Understanding Rebound Pain After Regional Anesthesia Resolution: Mechanistic Trial in Healthy Volunteers
Regional anesthesia decreases postoperative pain scores and opioid consumption, and may prevent chronic pain after surgery in patients undergoing surgery. However, some patients experience an increase of pain into the severe range when the nerve block wears off, also known as rebound pain. The investigators are studying if a nerve block (numbing injection) in the arm causes hyperalgesia (increased pain) when the nerve block is wearing off.
Read the detailed description
This is a prospective, randomized study in healthy volunteers who will undergo sensory testing using quantitative sensory testing (QST), complete psychosocial and pain questionnaires, and ultrasound-guided peripheral nerve block of the arm (axillary nerve block) in a supervised, monitored setting (BWH Clinical Investigation Center). The investigators plan to assess the association between different QST modalities at different time points pre- and post-nerve block resolution. Semi-structured interviews and qualitative analysis will be used to explore patient's experiences with nerve block placement.
- Conditions
- Regional Anesthesia Morbidity, Pain, Acute, Healthy
- Being tested
- Mepivacaine
- Keywords
- Healthy volunteer, Regional anesthesia, Rebound pain
- Medical subject headings
- Acute Pain
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
MepivacaineDrug
Also called Prilocaine
Injection of 1.5% Mepivacaine in nerve block
| Study group | Role | What they receive |
|---|---|---|
| Block upper extremity (arm) | Experimental | Upper extremity with a nerve block Receives: Drug: Mepivacaine |
| Control upper extremity (arm) | No intervention | Upper extremity without a nerve block |
What is being measured
The primary outcome is the main question the study is designed to answer.
Heat pain detection threshold at time 1 hr
Heat pain detection threshold (°C) between block arm and control arm using a heat probe at 1 hour after nerve block resolution
Measured: 1 hour after nerve block resolution
Secondary outcomes (5)
Heat pain detection threshold and tolerance
Heat pain detection threshold and tolerance (°C) between block arm and control arm using a heat probe at different time points up to 3 hours nerve block resolution
Measured: 0-3 hours after nerve block resolution
Pressure pain threshold and tolerance
Pressure pain threshold and tolerance (N of force) between block arm and control arm using an algometer at different time points up to 3 hours nerve block resolution
Measured: 0-3 hours after nerve block resolution
Temporal summation and sharp pain
Temporal summation and sharp pain (evaluated by numerical rating scale 0-10 pain score) between block arm and control arm using a pinprick device at different time points up to 3 hours nerve block
Measured: 0-3 hours after nerve block resolution
Light touch detection
Light touch detection (mN of force) between block arm and control arm using von Frey filaments at different time points up to 3 hours nerve block
Measured: 0-3 hours after nerve block resolution
Light touch pain threshold
Light touch pain threshold (mN of force) between block arm and control arm using von Frey filaments at different time points up to 3 hours nerve block
Measured: 0-3 hours after nerve block resolution
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Aug 2023
- Study start28 Sep 2023
- Primary completion28 May 2024
- Study completion28 May 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Regional Anesthesia MorbidityStudies of the same condition, open and under way.
- More trials run by Brigham and Women's HospitalThe sponsor's other registered studies.
- 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 1
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Participants will be randomized to which arm will receive a nerve block.
- Masking
- None (open label)
- Enrolment
- 40 participants (actual)
Sponsor and investigators
- Lead sponsor
- Brigham and Women's Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Yun-Yun K. Chen, Brigham and Women's Hospital
- Investigators
- Yun-Yun K Chen, MD, Principal investigator, Brigham and Women's Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06005480
- Sponsor's protocol ID
- 2023P001767
- Status last verified
- Jun 2024
- First submitted
- 16 Jul 2023
- Last updated
- 5 Nov 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Chen YK, Wilson JM, Collins PW, Gokul SR, Lirk P, Schreiber KL. Evaluation of Postblock Hypersensitivity Using Quantitative Sensory Testing before, during, and after Axillary Brachial Plexus Block Resolution in Healthy Volunteers. Anesthesiology. 2026 Aug 1;145(2):322-332. doi: 10.1097/ALN.0000000000006082. Epub 2026 Jul 14.
PubMed 42359695
Study at a glance
From the registry record, last updated by the sponsor on 5 Nov 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Understanding Rebound Pain After Regional Anesthesia Resolution: Mechanistic Trial in Healthy Volunteers
- ClinicalTrials.gov ID
- NCT06005480
- Acronym / sponsor ID
- 2023P001767
- Conditions
- Regional Anesthesia Morbidity, Pain, Acute, Healthy
- Keywords
- Healthy volunteer, Regional anesthesia, Rebound pain
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 40 participants (actual)
- Lead sponsor
- Brigham and Women's HospitalUniversity, hospital or other
- Study start
- 28 Sep 2023 (actual)
- Primary completion
- 28 May 2024 (actual)
- Study completion
- 28 May 2024 (actual)
- First posted
- 22 Aug 2023 (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.
Regional anesthesia decreases postoperative pain scores and opioid consumption, and may prevent chronic pain after surgery in patients undergoing surgery. However, some patients experience an increase of pain into the severe range when the nerve block wears off, also known as rebound pain. The investigators are studying if a nerve block (numbing injection) in the arm causes hyperalgesia (increased pain) when the nerve block is wearing off.
Detailed description
This is a prospective, randomized study in healthy volunteers who will undergo sensory testing using quantitative sensory testing (QST), complete psychosocial and pain questionnaires, and ultrasound-guided peripheral nerve block of the arm (axillary nerve block) in a supervised, monitored setting (BWH Clinical Investigation Center). The investigators plan to assess the association between different QST modalities at different time points pre- and post-nerve block resolution. Semi-structured interviews and qualitative analysis will be used to explore patient's experiences with nerve block placement.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- Participants will be randomized to which arm will receive a nerve block.
| Arm | Type | Receives |
|---|---|---|
| Block upper extremity (arm) | Experimental | Drug: MepivacaineUpper extremity with a nerve block |
| Control upper extremity (arm) | No intervention | –Upper extremity without a nerve block |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Age ≥ 18 years old, ≤ 65 years old
- BMI >18, < 35
- Able to speak and understand English
- Willingness to undergo psychophysical testing (e.g., QST, pain questionnaires)
- Willingness to have nerve block performed
Key exclusion criteria (9 listed)
- Ongoing acute or chronic pain in upper extremities
- Skin or tissue infection affecting upper extremities
- Previous hypersensitivity to mepivacaine or lidocaine
- Previous neuropathy (numbness, paresthesia, or motor weakness) in either upper extremity
- Loss of any limb
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 |
|---|---|---|
| MepivacaineAlso: PrilocaineInjection of 1.5% Mepivacaine in nerve block | Drug | Block upper extremity (arm) |
Primary outcome
Heat pain detection threshold at time 1 hr
Time frame: 1 hour after nerve block resolution
Heat pain detection threshold (°C) between block arm and control arm using a heat probe at 1 hour after nerve block resolution
5 secondary outcomes
Heat pain detection threshold and tolerance
Time frame: 0-3 hours after nerve block resolution
Pressure pain threshold and tolerance
Time frame: 0-3 hours after nerve block resolution
Temporal summation and sharp pain
Time frame: 0-3 hours after nerve block resolution
Light touch detection
Time frame: 0-3 hours after nerve block resolution
Light touch pain threshold
Time frame: 0-3 hours after nerve block resolution
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 5 Nov 2025.
- Derived from this study: PubMed 42359695Chen YK, Wilson JM, Collins PW, Gokul SR, Lirk P, Schreiber KL. Evaluation of Postblock Hypersensitivity Using Quantitative Sensory Testing before, during, and after Axillary Brachial Plexus Block Resolution in Healthy Volunteers. Anesthesiology. 2026 Aug 1;145(2):322-332. doi: 10.1097/ALN.0000000000006082. Epub 2026 Jul 14.
- Mass General Brigham Rally FlyerLink provided by the sponsor.
- Individual participant dataSharing planned: No
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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.
Yun-Yun K Chen, MD principal investigator
Brigham and Women's Hospital
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing Mepivacaine in people with Regional Anesthesia Morbidity and Pain, Acute, run by Brigham and Women's Hospital at 1 site in United States.
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 5 inclusion and 9 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 5 Nov 2025. 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 United States. 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.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
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?
Heat pain detection threshold at time 1 hr (time frame: 1 hour after nerve block resolution). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06005480, which also lists 1 linked publication.
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 5 Nov 2025.