Healthy, Pain, Acute, Regional Anesthesia Morbidity
Conditions
Keywords
Healthy volunteer, Regional anesthesia, Rebound pain
Brief 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. 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.
Interventions
DRUGMepivacaine
Injection of 1.5% Mepivacaine in nerve block
Sponsors
Brigham and Women's Hospital
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
NONE
Intervention model description
Participants will be randomized to which arm will receive a nerve block.
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
* 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
Exclusion criteria
* 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 * History of alcohol or drug abuse * Currently pregnant or breastfeeding * History of seizure or epilepsy
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Heat pain detection threshold at time 1 hr | 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 |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Pressure pain threshold and tolerance | 0-3 hours after nerve block resolution | 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 |
| Temporal summation and sharp pain | 0-3 hours after nerve block resolution | 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 |
| Light touch detection | 0-3 hours after nerve block resolution | 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 |
| Light touch pain threshold | 0-3 hours after nerve block resolution | 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 |
| Heat pain detection threshold and tolerance | 0-3 hours after nerve block resolution | 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 |
Other
| Measure | Time frame | Description |
|---|---|---|
| Temperature change | 6-8 hours | To observe the change in temperature between block arm and control arm (°C) pre, during, and post nerve block |
| Patient's experiences with nerve block | 6-8 hours | Semi-structured interviews will be used to explore patient's experiences with nerve block placement using an immersion/crystallization approach to identify emergent themes |
| Pain catastrophizing and gender differences | 6-8 hours | Correlation between situational pain catastrophizing (0-24 scale) and gender |
Countries
United States
Outcome results
None listed