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Understanding Rebound Pain After Regional Anesthesia Resolution in Healthy Volunteers

Phase 1
Completed
Conditions
Regional Anesthesia Morbidity
Pain, Acute
Healthy
Interventions
Registration Number
NCT06005480
Lead Sponsor
Brigham and Women's Hospital
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.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
58
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

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Block upper extremity (arm)MepivacaineUpper extremity with a nerve block
Primary Outcome Measures
NameTimeMethod
Heat pain detection threshold at time 1 hr1 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
NameTimeMethod
Light touch detection0-3 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 threshold0-3 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 tolerance0-3 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 tolerance0-3 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 pain0-3 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

Trial Locations

Locations (1)

Brigham and Women's Hospital

🇺🇸

Boston, Massachusetts, United States

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