Investigating a placebo for nerve blocks to improve clinical trials

The Impact of Local Anesthetic Dilution on the Possibility of Blinding Studies Involving Peripheral Nerve Blocks. A Randomized, Prospective, Monocentric Study on Volunteers

Not applicable Interventional Balgrist University Hospital · NCT06668116

This study is testing a new fake anesthetic that feels like a real nerve block to help improve future research on pain management treatments.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment30 (estimated)
Ages18 Years to 65 Years
SexAll
SponsorBalgrist University Hospital Academic / other
Locations2 sites (Zurich, ZH and 1 other locations)
Trial IDNCT06668116 on ClinicalTrials.gov

What this trial studies

This study aims to identify an effective placebo anesthetic that mimics the sensations of a real nerve block without providing actual pain relief. By developing a convincing placebo, the researchers hope to enhance the validity of future placebo-controlled studies on nerve blocks, which are essential for understanding their efficacy in pain management. The study will involve healthy participants aged 18 to 65, who will receive either the active anesthetic or the placebo. The ultimate goal is to establish a methodology that allows for rigorous investigations into the effectiveness of nerve blocks.

Who should consider this trial

Good fit: Ideal candidates for this study are healthy adults aged 18 to 65 with no history of chronic or acute pain.

Not a fit: Patients with known allergies to local anesthetics, chronic pain conditions, or those taking pain-modulating medications may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to more reliable evidence regarding the efficacy of nerve blocks, ultimately improving pain management strategies for patients.

How similar studies have performed: While the approach of developing a convincing placebo for nerve blocks is novel, similar methodologies have shown promise in other areas of clinical research.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* ASA I - II, both sexes
* ≥ 18 years old
* \< 65 years old
* Written informed consent as documented by signature

Exclusion Criteria:

* Known allergy or hypersensitivity to a ropivacaine, amide local anesthetics or ultrasound gel
* Any history of chronic or acute pain at the moment of enrollment into the study
* Treatment with any substance having a relation to pain or pain modulation (antidepressants, opioids, benzodiazepines, anticonvulsants)
* Intake of any analgesic 48 hours prior to the conduction of any of the study stages
* Severe coagulopathy
* History of cardiovascular disease
* History of alcohol abuse or the intake of psychotropic drugs
* Pregnancy, ruled out by history
* Infection at the injection site or a systemic infection
* Fever of unknown origin
* Motor or sensory abnormalities in the arm
* Previous enrollment into the current study

Where this trial is running

Zurich, ZH and 1 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions HealthyPeripheral nerve blocksPlacebo-controlled studiesBlinding in clinical trials
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.