Transcutaneous Auricular Vagus Nerve Stimulation for Managing Pain: A Scoping Review

To examine the pain conditions that have been studied using transcutaneous auricular vagus nerve stimulation (taVNS), the various methods and dosage configurations used, as well as identify current gaps in the literature.

Scoping review with the literature search and reporting guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement-extension for scoping reviews.

A systematic search was conducted across four databases-Pubmed/Medline (n = 24), PsycInfo (n = 218), CINAHL (n = 114), and Scopus (n = 52)-comprising a total of 408 publications from peer-reviewed journals. The MeSH terms used for the search were: "transcutaneous nerve stimulation AND vagus nerve stimulation" along with "transcutaneous vagus nerve stimulation OR taVNS AND pain" with filters placed for clinical trials published between 2014 to March 2024.

A total of 26 publications met eligibility for inclusion in this scoping review. The most common types of pain that have been used to evaluate the efficacy of taVNS include episodic migraine without aura, rheumatoid arthritis, fibromyalgia, irritable bowel syndrome, and chronic low back pain. The device type and settings, dosage, and placement of electrodes varied across studies. Identified research gaps include the need to determine optimal dosage for the pain condition under study, inclusion of measures to evaluate intervention fidelity, long-term outcomes and symptoms that co-occur with pain, and subanalyses to examine outcomes among various sociodemographic variables.

There is increasing evidence supporting the potential of taVNS in pain management. Further research is necessary to comprehensively evaluate its efficacy, underlying mechanisms, and to optimize its clinical application.

The findings indicate a growing body of evidence for effective use of taVNS for pain management, along with reducing co-occurring symptoms, such as depression. Nurses should be knowledgeable about this treatment option and collaborate with other healthcare professionals to develop best practices for the use of this technology in practice.