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Not yet recruiting NCT07429292

SPARK Study - Sympathetic Periarterial Radial Block in Healthy Volunteers

Phase IV Interventional Healthy Volunteers Sympathetic Activity

For patients and families

In plain language

An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.

What is being studied
The protocol lists: Lidocaine 2%.
Who it may be relevant to
Registry conditions: Healthy Volunteers, Sympathetic Activity. Basic parameters: 18 years — 50 years · All.
What needs checking
Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
Where it takes place
United States
Next step
Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →

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Official title

SPARK Study - Sympathetic PeriArterial Radial blocK Study

Overview

The SPARK Study evaluates changes in peripheral sympathetic vasomotor activity following a targeted, ultrasound-guided periarterial sympathetic block of the distal radial artery in healthy volunteers. Autonomic reactivity will be assessed before and after the block using digit-specific pulse-amplitude index and infrared thermography during standardized cold pressor testing.

Interventions

  • Drug Lidocaine 2%
    Small-volume injection (5 mL) of 2% lidocaine around radial artery under ultrasound guidance.

Primary outcome measures

  • Pulse amplitude index (PAI) [Time frame: PAI will be measured at: 1) Baseline; 2) after the first cold pressor test at 0, 5, 10, and 15 minutes; 3) after the sympathetic block at 5 and 10 minutes; 4) after the second cold pressor test at 0, 5, 10, and 15 minutes.]
  • Hand temperature [Time frame: Thermal images will be obtained at: 1) Baseline; 2) after the first cold pressor test at 0, 5, 10, and 15 minutes; 3) after the sympathetic block at 5 and 10 minutes; 4) after the second cold pressor test at 0, 5, 10, and 15 minutes.]
Secondary outcome measures (3)
  • Temporal Changes in Cold Pressor Test-Induced Vasomotor Responses Pre- and Post-Block [Time frame: Data will be obtained at: 1) Baseline; 2) after the first cold pressor test at 0, 5, 10, and 15 minutes; 3) after the sympathetic block at 5 and 10 minutes; 4) after the second cold pressor test at 0, 5, 10, and 15 minutes.]
  • Change in Vasomotor Measures in the Fifth Finger [Time frame: PAI and thermal images will be measured at: 1) Baseline; 2) after the first cold pressor test at 0, 5, 10, and 15 minutes; 3) after the sympathetic block at 5 and 10 minutes; 4) after the second cold pressor test at 0, 5, 10, and 15 minutes.]
  • Change in Vasomotor Measures in the Contralateral Index Finger [Time frame: PAI and thermal images will be measured at: 1) Baseline; 2) after the first cold pressor test at 0, 5, 10, and 15 minutes; 3) after the sympathetic block at 5 and 10 minutes; 4) after the second cold pressor test at 0, 5, 10, and 15 minutes.]

Eligibility criteria

Inclusion criteria

  • Age 18-50 years
  • ASA physical status I-II
  • Able to understand and provide informed consent
  • Able to comply with study procedures and follow-up
  • Two hands with 5 intact digits and no significant upper extremity injury

Exclusion criteria

  • Allergy to lidocaine or similar anesthetics
  • Allergy to adhesives or ultrasound gel
  • Neuromuscular, autonomic, or major vascular disorders affecting upper extremities
  • Peripheral neuropathy
  • Raynaud's phenomenon or digital ischemia
  • Coagulopathy or anticoagulation
  • Active skin infection near block site
  • Pregnancy
  • BMI > 35 kg/m²
  • Inability to tolerate cold exposure
  • Any condition interfering with study conduct

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Allocation
Randomized
Model
Parallel assignment
Masking
Single blind
Primary purpose
Basic science

Study locations

United States · 1 center
  • Duke University Medical Center — Durham

Identifiers

NCT: NCT07429292 · Pro00119632

Primary sources (government registries)

View this study on ClinicalTrials.gov ↗