An interventional study of Transcutaneous vagal nerve stimulation and Sham (No Treatment) in Post Operative Delirium, Cognitive Impairment and Vagus Nerve Stimulation, sponsored by Northwestern University. Recruiting at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-05-28.
Sponsored by Northwestern University · Not applicable, Interventional, and Treatment
This study will examine whether noninvasive, transcutaneous vagal nerve stimulation (tcVNS) can help restore consciousness in patients in the operating room and the Post Anesthesia Care Unit (PACU). The study will also investigate if tcVNS can expedite discharge from the PACU and examine whether tcVNS administerd in the PACU helps reduce delirium and depression after surgery. The study will also evaluate whether tcVNS speeds cognitive recovery from emergence of anesthesia and surgery.
751 studies on the registry are indexed under Emergence Delirium; 262 are open to participants now.
This study's planned enrollment of 40 is below the median of 120 across 464 interventional studies indexed under Emergence Delirium.
Browse Emergence Delirium studies →Northwestern University is the lead sponsor of 1,423 studies on the registry; 198 are open to participants now.
Of its 105 completed or terminated interventional studies of FDA-regulated products, 78 (74%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Short tests of memory and thinking, each scored out of 30. Lower scores suggest more difficulty; criteria give a range, either to include people with memory problems or to leave them out.
On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.
The study may name a correction formula and a limit in milliseconds, often around 450–480.
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
MMSE and MoCA
Short tests of memory and thinking, each scored out of 30. Lower scores suggest more difficulty; criteria give a range, either to include people with memory problems or to leave them out.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
QT and QTc
On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.
The study may name a correction formula and a limit in milliseconds, often around 450–480.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
LVEF (left ventricular ejection fraction)
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
NYHA class (heart failure)
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ECG (electrocardiogram)
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Transcutaneous vagal nerve stimulation (tcVNS)
Device: Transcutaneous vagal nerve stimulation
Sham transcutaneous vagal nerve stimulation (Sham tcVNS)
Device: Sham (No Treatment)
The tcVNS device utilized in this study is not an implanted device, but rather is solely operated outside of the body by affixing it around the patient's ear. The device delivers stimulation of the vagus nerve at designated intensity, interval, and frequency.
The stimulator is flipped upside down so that the participant does not receive stimulation of the vagal nerve.
Aim 1: Primary Endpoint 1: Determine if administering auricular tcVNS enhances the speed of recovery of anesthesia.
Time in minutes to a Patient State Index (PSI) (Sedline Sedation Monitor) score of 85. The PSI is a quantitative score derived from 4 channel EEG monitoring of the frontal and prefrontal cortex for assessing level of consciousnes during sedation and general anesthesia. The score ranges from 0 (EEG supression) -100 (fully awake). A PSI range of 25-50 indicates optimal hypnotic state for general anesthesia
Time frame: 24 Hours
Aim1:Primary Endpoint 2 : Richmond Agitation Sedation Scale (RASS Score)
The Richmond Agitation-Sedation Scale (RASS) is a 10-point validated scale used to measure patient sedation levels in post-anesthesia care unit, ranging from +4 (combative) to -5 (unarousable). A score of 0 is "alert and calm".Measured on arrival to PACU then at 10,15,30,45,60 minutes after admission to PACU.
Time frame: 1 Hour
Aim 2: Primary Endpoint 1: Post Anesthesia Care Unit Discharge (PACU)
Admission time to the PACU to discharge from PACU in minutes elapsed.
Time frame: 3 Hours
Aim 2: Primary Endpoint 2: Discharge from Hospital
Time from Post Anesthesia Care Unit discharge to discharge from the hospital in days/minutes
Time frame: From PACU discharge (average of two hours post-surgical end time) to study completion (average of two days)
Aim 3: Primary Endpoint 1: Post Anesthesia Care Unit delirium
Comparison between active and sham tcVNS on delirium scores in the PACU at 30, 45 and 60 minutes after admission to the PACU. The 3D Confusion Assessment Method (3D CAM) will be administered at 30, 45 and 60 minutes after admission to PACU. The 3D CAM diagnostic tool scores delirium based on four core features, where Feature 1 (Acute Change) AND Feature 2 (Inattention) MUST be present, plus either Feature 3 (Disorganized Thinking) or Feature 4 (Altered Consciousness). It offers a severity score (3D-CAM-S) ranging from 0-20, with higher scores indicating more severe symptoms (0/20 low 20/20 high
Time frame: From PACU arrival to one hour post-PACU arrival
Aim 3: Primary Endpoint 1a: Post Anesthesia Care Delirium
Delirium scores 30 days after discharge from the hospital. The 3D Confusion Assessment Method (3D CAM) will be administered 30 days after discharge from the hospital. The 3D CAM diagnostic tool scores delirium based on four core features, where Feature 1 (Acute Change) AND Feature 2 (Inattention) MUST be present, plus either Feature 3 (Disorganized Thinking) or Feature 4 (Altered Consciousness). It offers a severity score (3D-CAM-S) ranging from 0-20, with higher scores indicating more severe symptoms (0/20 low 20/20 high
Time frame: 30 Days after discharge
Aim3:Primary Endpoint 1b: PHQ-9
The Patient Health Questionnaire Nine (PHQ-9) is a 9-question survey used to measure patient depression potential, ranging 1-27 (1 low possibility of depression to 27 highest potential for depression. Tested at baseline, post operative day 1 and 30 days post discharge from hospital.
Time frame: 30 days
Aim 3: Secondary Endpoint 1:EEG Monitoring Data
Continuous EEG monitoring data to be evaluated for patterns associated with delirium (polymorphiic delta waves, generalized slowing quantified as delta range vs alpha range power
Time frame: From pre-surgical EEG placement (i.e. approximately 30 minutes before surgery) through study completion (an average of 2 days)
The Montreal Cognitive Assessment (MoCA) evaluations
The MoCA includes measures of memory recll, visuospatial processing, executive functions, attention, language, abstract reasoning and orientation to time and place. Administered baseline and post operative day 2. 0-30 point scale, 26 and above is normal, 18-25 mild cognitive dysfunction, 10-17 is moderate dysfunction and 0-10 is severe dysfunction.
Time frame: 48 hours
SF-36 Survey
The 36-Item Short Form Survey (SF-36) is a self-reported patient outcome measure that assesses physical and mental health across eight domains, including functioning, pain, and vitality. Score ranges from 0 low to 100 high. The higher the score the better the overall health. Administered at baseline and 30 days after discharge.
Time frame: 30 days
Neuro Qol Cognition Function Short Form
This is a brief self-report tool used to measure perceived difficulties in everyday cognitive tasks. It is a portion of of the Quality of Life in Neurological Disorders (Neuro-QoL). he short form uses T-scores, which standardize results against a reference population (typically the U.S. general population).There are 8 questions. A T-score of 50 represents the average for the reference population. A high score indicates better perceived cognitive function. Completed at baseline and 30 days.
Time frame: 30 Days
Neuro- QOL
Neuro-QoL(Quality of Life in Neurological Disorders) is a measurement system that evaluates and monitors the physical, mental, and social effects experienced by adults who may have neurological conditions. Tested at baseline and 30 days.
Time frame: 30 Days
DRS-R-98
The Delirium Rating Scale (DRS-R-98) is a tool for assessing symptom severity and diagnosing delirium in clinical settings. This sixteen-item scale in a thirteen-item severity section and three diagnostic items, tracking changes over a twenty-four-hour period. The 16-item, clinician-rated tool used to diagnose and measure the severity of delirium. It consists of 13 severity items (scored 0-3) and 3 diagnostic items (scored 0-2 or 0-3), with a maximum total score of 46. Higher scores indicate more severe delirium, with scores of15 or greater than or greater than 17.5 often indicating delirium. Assessed at Day 1 and day 2 post operative.
Time frame: 48 hours
DigitSpan Test
Digit Span test measures auditory short-term memory and working memory capacity by asking participants to repeat sequences of digits in forward, reversed, or ordered sequences. It is used to measure cognitive processing, attention, and executive function, usually contains 5-9 digits. scoring typically awards one point for each correctly repeated sequence. Performed post operative day 1and 2.
Time frame: 48 Hours
Plan to share: No
Started Apr 2026 (actual). Primary completion is estimated for Dec 2028, 32 months after the start.
Of 184 non-industry interventional studies with no phase under Emergence Delirium, half reached primary completion within 19 months of starting (the median), counting those still running; a quarter within 7 and three quarters within 36. This study's planned 32 months is above that.
Counting every sponsor, half of 184 studies reached it within 19 months; a quarter within 7 and three quarters within 36.
How these figures are worked out, and which studies are left out of them.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.