Understanding Rebound Pain After Regional Anesthesia Resolution in Healthy Volunteers

Sponsor

Brigham and Women's Hospital (Other)

Overall Status

Not yet recruiting

CT.gov ID

NCT06005480

Collaborator

(none)

Enrollment

Arms

Anticipated Duration (Months)

Study Details

Study Description

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.

Condition or Disease	Intervention/Treatment	Phase
Regional Anesthesia Morbidity Pain, Acute Healthy	Drug: Mepivacaine	Phase 1

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

Study Type:

Interventional

Anticipated Enrollment :

40 participants

Allocation:

Randomized

Intervention Model:

Parallel Assignment

Intervention Model Description:

Participants will be randomized to which arm will receive a nerve block.Participants will be randomized to which arm will receive a nerve block.

Masking:

None (Open Label)

Primary Purpose:

Basic Science

Official Title:

Understanding Rebound Pain After Regional Anesthesia Resolution: Mechanistic Trial in Healthy Volunteers

Anticipated Study Start Date :

Sep 1, 2023

Anticipated Primary Completion Date :

Dec 1, 2024

Anticipated Study Completion Date :

Dec 1, 2024

Arms and Interventions

Arm	Intervention/Treatment
Experimental: Block upper extremity (arm) Upper extremity with a nerve block	Drug: Mepivacaine Injection of 1.5% Mepivacaine in nerve block Other Names: Prilocaine
No Intervention: Control upper extremity (arm) Upper extremity without a nerve block

Arm

Intervention/Treatment

Experimental: Block upper extremity (arm)

Upper extremity with a nerve block

Drug: Mepivacaine

Injection of 1.5% Mepivacaine in nerve block

Other Names:

Prilocaine

No Intervention: Control upper extremity (arm)

Upper extremity without a nerve block

Outcome Measures

Primary Outcome Measures

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 Outcome Measures

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
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

Other Outcome Measures

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

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years to 65 Years

Sexes Eligible for Study:

All

Accepts 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