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Postoperative Delirium (POD)HRVPODNCT07783464

Heart Rate Variability Changes and Postoperative Delirium After Major Abdominal Surgery

An observational study of Postoperative Delirium (POD) and Heart Rate Variability (HRV), run by The First Affiliated Hospital with Nanjing Medical University at 1 site in China.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

This prospective observational cohort study aims to investigate whether early postoperative changes in heart rate variability (HRV) relative to baseline are associated with the development of postoperative delirium (POD) in older patients undergoing elective major abdominal surgery under general anesthesia. Read more about this study

Who is it for?
Ages 65 to 85 years
What is being tested?
Perioperative Heart Rate Variability Changes
How many people
500 participants
Where
1 siteChina
Study dates
21 Sep 2026to 15 May 2027
Phase
Observational
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 65 to 85 years
  • All sexes
  • No healthy volunteers
  • Older adult

Study population: Older patients aged 65 to 85 years undergoing elective major abdominal surgery under general anesthesia will be prospectively enrolled. Perioperative heart rate variability will be assessed before surgery and within 24 hours after surgery, and participants will be followed for the occurrence of postoperative delirium during the first 7 postoperative days.

Who may be able to join

  • Patients admitted to Jiangsu Provincial People's Hospital who are scheduled to undergo elective major abdominal surgery under general anesthesia.
  • Older patients aged 65 to 85 years.
  • Expected postoperative hospital stay of ≥7 days.
  • Body mass index (BMI) between 18.5 and 28.0 kg/m².
  • American Society of Anesthesiologists (ASA) physical status classification I-III.
  • Patients who are conscious, mentally competent, and able to cooperate with heart rate variability (HRV) measurements, questionnaire assessments, and follow-up evaluations.
  • Patients who voluntarily participate in the study and provide written informed consent.

Who cannot join

  • Patients with ASA physical status classification ≥IV or patients with end-stage cancer.
  • Patients with implanted cardiac pacemakers, implantable cardioverter-defibrillators, or other electronic devices that may interfere with ECG signal acquisition.
  • Patients with severe or unstable cardiovascular diseases, including but not limited to acute coronary syndrome, symptomatic bradycardia, sick sinus syndrome, second-degree or higher atrioventricular block, atrial fibrillation, atrial flutter, frequent premature beats, or other arrhythmias that may affect heart rate variability analysis.
  • Patients with diseases affecting autonomic nervous system function, including confirmed primary or secondary autonomic dysfunction, such as Parkinson's disease, multiple system atrophy, severe diabetic autonomic neuropathy, severe peripheral neuropathy, poorly controlled hyperthyroidism or hypothyroidism, and systemic amyloidosis.
  • Patients with a history of organic central nervous system diseases or psychiatric disorders, including major traumatic brain injury, stroke (ischemic or hemorrhagic), intracranial mass lesions, epilepsy, schizophrenia, bipolar disorder, major depressive disorder, or other severe psychiatric disorders.
  • Patients with severe baseline cognitive impairment or inability to complete cognitive assessments, including any of the following: (1) preoperative baseline Montreal Cognitive Assessment (MoCA) score <14 points; (2) previously diagnosed dementia, preoperative delirium, coma, or other severe disturbances of consciousness; or (3) inability to complete standardized cognitive assessments due to severe visual impairment, hearing impairment, language barriers, or other causes.
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  • Patients unable to undergo HRV measurement within 24 hours after surgery, including those with severe perioperative complications, emergency reoperation, extremely unstable vital signs, or requiring continuous deep sedation after surgery.
  • Patients who have taken anticholinergic medications, beta-blockers, antiarrhythmic drugs, or other medications that may significantly affect autonomic function within 1 month before study enrollment.
  • Patients who are currently participating in any other clinical trial.

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

China1 site, 1 recruiting
  • The First Affiliated Hospital with Nanjing Medical University

    Nanjing, Jiangsu, 210029

    13813955365, wujunbei@gmail.com

    wujunbei@gmail.com

    Recruiting

Other trials in China

About this study

Official title: Predictive Value of Early Postoperative Heart Rate Variability Changes From Baseline for Postoperative Delirium in Older Adults Undergoing Major Abdominal Surgery: A Prospective Cohort Study

This prospective observational cohort study aims to investigate whether early postoperative changes in heart rate variability (HRV) relative to baseline are associated with the development of postoperative delirium (POD) in older patients undergoing elective major abdominal surgery under general anesthesia. Patients aged 65-85 years will be enrolled. Resting HRV will be measured at 10:00 AM on the day of surgery before anesthesia induction and at the same time point on the first postoperative day using a validated heart rate monitoring device. HRV parameters will be derived from standardized 5-minute recordings. Changes in HRV parameters from baseline will be calculated, and their associations with POD occurrence will be evaluated. Postoperative delirium will be assessed daily from 24 hours after surgery to postoperative day 7, using the 3-Minute Diagnostic Interview for Confusion Assessment Method (3D-CAM). The study will also explore the potential utility of HRV-derived markers for early POD risk stratification. Approximately 500 participants will be enrolled.

Read the detailed description

Postoperative delirium (POD) is a common neurocognitive complication following major surgery in older adults and is associated with increased morbidity, prolonged hospitalization, and adverse clinical outcomes. However, objective and easily obtainable biomarkers for early identification of patients at high risk of POD remain limited.

Heart rate variability (HRV) reflects autonomic nervous system regulation and may provide a non-invasive marker of physiological stress and impaired autonomic adaptability. Major abdominal surgery induces substantial systemic stress responses, including inflammation, neuroendocrine activation, and autonomic disturbances. Whether early postoperative alterations in HRV are associated with subsequent POD development remains unclear.

This is a single-center, prospective observational cohort study. Patients aged 65-85 years undergoing elective major abdominal surgery under general anesthesia will be consecutively enrolled. Baseline demographic characteristics, comorbidities, frailty status, cognitive function, and perioperative clinical variables will be collected.

Resting HRV will be measured at 10:00 AM on the day of surgery before anesthesia induction and again at the same time point on the first postoperative day using a validated heart rate monitoring device. HRV analysis will be performed based on standardized 5-minute recordings in accordance with established recommendations for short-term HRV assessment. Time-domain, frequency-domain, and nonlinear HRV parameters will be calculated.

Postoperative delirium will be assessed daily from 24 hours after surgery to postoperative day 7 using the 3-Minute Diagnostic Interview for Confusion Assessment Method (3D-CAM). Additional clinical outcomes include delirium severity, delirium duration, postoperative cognitive function, quality of recovery, postoperative nausea and vomiting, and length of hospital stay.

The primary objective is to evaluate the association between early postoperative HRV changes and the occurrence of POD after adjustment for clinically relevant confounding factors, including age, baseline cognitive function, frailty status, surgical duration, and baseline HRV. Secondary analyses will explore the relationship between representative HRV markers and postoperative clinical outcomes and assess their potential utility for early POD risk stratification.

Being tested
Perioperative Heart Rate Variability Changes
Keywords
Postoperative delirium, Heart rate variability, Major abdominal surgery, Elderly patients
Medical subject headings
Emergence Delirium

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Perioperative Heart Rate Variability ChangesOther

    Heart rate variability will be measured using standardized 5-minute recordings at predefined time points: 10:00 AM on the day of surgery before surgery and 10:00 AM on postoperative day 1 (within 24 hours after surgery). Perioperative changes in heart rate variability will be evaluated as an observational exposure to investigate their association with postoperative delirium in older patients undergoing elective major abdominal surgery under general anesthesia.

Study groups in NCT07783464
Study groupRoleWhat they receive
Elderly Patients Undergoing Elective Major Abdominal SurgeryElderly patients undergoing elective major abdominal surgery under general anesthesia will be prospectively enrolled and followed for postoperative delirium.
Receives: Other: Perioperative Heart Rate Variability Changes

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Occurrence of postoperative delirium within 7 days after surgery

    Postoperative delirium will be assessed daily from postoperative day 1 to postoperative day 7 using the Chinese version of the 3-Minute Diagnostic Interview for CAM-defined Delirium (3D-CAM). Delirium diagnosis will be based on the Confusion Assessment Method (CAM) algorithm.

    Measured: Postoperative day 1 to postoperative day 7 after surgery

Secondary outcomes (4)
  1. Severity of postoperative delirium

    The severity of postoperative delirium will be assessed using the Delirium Rating Scale-Revised-98 (DRS-R-98) among patients who develop postoperative delirium. The DRS-R-98 scores range from 0 to 46, with higher scores indicating greater delirium severity (worse outcome).

    Measured: Postoperative day 1 to postoperative day 7 after surgery

  2. Duration of postoperative delirium

    The duration of postoperative delirium episodes will be recorded from the first diagnosis of delirium until resolution during the postoperative assessment period.

    Measured: Postoperative day 1 to postoperative day 7 after surgery

  3. Change in cognitive function after surgery

    Cognitive function will be assessed using the Montreal Cognitive Assessment (MoCA). Scores range from 0 to 30, with higher scores indicating better cognitive function (better outcome).

    Measured: Postoperative day 7

  4. Quality of recovery after surgery

    Quality of recovery will be assessed using the 15-item Quality of Recovery Questionnaire (QoR-15). Scores range from 0 to 150, with higher scores indicating better quality of recovery (better outcome).

    Measured: Postoperative day 7

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted24 Aug 2026
  2. Study start21 Sep 2026
  3. Primary completion30 Apr 2027 (estimated)
  4. Study completion15 May 2027 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Observational model
Cohort
Time perspective
Prospective
Enrolment
500 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07783464
Sponsor's protocol ID
2026-SR-0106
Acronym
HRVPOD
Status last verified
Sep 2026
First submitted
18 Aug 2026
Last updated
28 Sep 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No: Individual participant data will not be shared with other researchers. The study involves detailed perioperative clinical information, heart rate variability data, and cognitive and delirium assessments collected from older surgical patients. Due to privacy protection, ethical considerations, and the absence of a predefined data-sharing plan in the informed consent process, individual participant data will not be made publicly available.

Publications

  • Schaffarczyk M, Rogers B, Reer R, Gronwald T. Validity of the Polar H10 Sensor for Heart Rate Variability Analysis during Resting State and Incremental Exercise in Recreational Men and Women. Sensors (Basel). 2022 Aug 30;22(17):6536. doi: 10.3390/s22176536.

    PubMed 36081005
  • Heart rate variability: standards of measurement, physiological interpretation and clinical use. Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology. Circulation. 1996 Mar 1;93(5):1043-65. No abstract available.

    PubMed 8598068
  • Amit Patel K, Sethi A, Al Azazi E, McClurg C, Chowdhury T. The role of heart rate variability in predicting delirium: A systematic review and meta-analysis. J Clin Neurosci. 2024 Jun;124:122-129. doi: 10.1016/j.jocn.2024.04.028. Epub 2024 May 4.

    PubMed 38703472
  • Ernst G, Watne LO, Frihagen F, Wyller TB, Dominik A, Rostrup M. Decreases in heart rate variability are associated with postoperative complications in hip fracture patients. PLoS One. 2017 Jul 25;12(7):e0180423. doi: 10.1371/journal.pone.0180423. eCollection 2017.

    PubMed 28742855
  • Sun J, Zhang Q, Lin B, He M, Pang Y, Liang Q, Huang Z, Xu P, Que D, Xu S. Association Between Postoperative Long-Term Heart Rate Variability and Postoperative Delirium in Elderly Patients Undergoing Orthopedic Surgery: A Prospective Cohort Study. Front Aging Neurosci. 2021 May 31;13:646253. doi: 10.3389/fnagi.2021.646253. eCollection 2021.

    PubMed 34135747
  • Mazzeo AT, La Monaca E, Di Leo R, Vita G, Santamaria LB. Heart rate variability: a diagnostic and prognostic tool in anesthesia and intensive care. Acta Anaesthesiol Scand. 2011 Aug;55(7):797-811. doi: 10.1111/j.1399-6576.2011.02466.x. Epub 2011 Jun 9.

    PubMed 21658013

Questions about this trial

What is this clinical trial studying?

An observational study of Postoperative Delirium (POD) and Heart Rate Variability (HRV), run by The First Affiliated Hospital with Nanjing Medical University at 1 site in China.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 7 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: looking for participants now, as of the sponsor's last update on 28 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in China. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Junbei Wu (+86 13813955365, wujunbei88@sina.cn), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Occurrence of postoperative delirium within 7 days after surgery (time frame: Postoperative day 1 to postoperative day 7 after surgery). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07783464, which also lists 6 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 28 Sep 2026.

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