efficacy of TrAnsauricular Vagal Nerve Stimulation to reduce postoperative delirium severity: a double-blind randomised, sham-controlled feasibility study (TAVerNS)

efficacy of TrAnsauricular Vagal Nerve Stimulation to reduce postoperative delirium severity in surgical patients aged 60 years and older: a double-blind randomised, sham-controlled feasibility study (TAVerNS)

Status

Not yet recruiting

Phases

Unknown

Study type

Interventional

Source

ANZCTR

Registry ID

ACTRN12625001073493

Acronym

TAVerNS

Enrollment

Registered

2025-10-02

Start date

2025-11-03

Completion date

2027-01-25

Last updated

2025-10-06

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

None listed

Brief summary

Double-blind randomized sham-controlled trial. Transcutaneous auricular vagal nerve stimulation (taVNS) is a safe, non-invasive neuromodulation technique that delivers electrical stimulation to the auricular branch of the vagus nerve via electrodes placed on the tragus of the ear. Vagal nerve stimulation (VNS) is known to provoke brain arousal via release of noradrenaline and acetylcholine in cortex. Given there are no treatments for delirium, taVNS represents a paradigm shift in the approach, and would avoid polypharmacy effects that often contribute to treatment complexities in acutely ill older adults.

Interventions

Stimulation or Sham using a PROFILE TENS Machine Stimulation protocol: Stimulation on day of surgery (after incision closure) will be through the tragus using a standard taVNS machine. Stimulation will be delivered for 30 minutes (pulse width: 200 µs, frequency: 30 Hz) for each stimulation session (POD1 and 2 prior to assessments. Stimulation will be initiated at 10 mA, and turned down 2mA every 20 seconds until participants no longer feel it. This final value will be recorded. Bilateral taVNS was chosen because there may be improved neural plasticity responses and proven perioperative safety. Sham protocol: For the sham group, the same stimulation protocol will be followed, however electrodes will be connected to the earlobes to prevent vagus nerve stimulation. These will be turned off once the noticeable threshold is reached. This will be conducted by a member of the research team and hospital scientist (PhD). Case report files will collect start and end time of stimulation or sham and instance of needing to cease due to side effects.

Study design

Allocation

Randomised controlled trial

Intervention model

Parallel

Primary purpose

Prevention

Masking

Blinded (masking used) (Subject, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender

All

Age

60 Years to No maximum

Healthy volunteers

Inclusion criteria

1) Patients aged 60 years and over, 2) able to provide informed consent before surgery, 3) English speaking (for cognitive testing), 4) undergoing major non-cardiac, non-intracranial surgery (defined as a minimum anticipated stay of >2 days.

Exclusion criteria

1) Preexisting delirium or dementia, 2) cardiac arrythmia requiring therapy, 3) auricular dermatitis, 4) life expectancy <30 days.

Outcome results