Heart Rate Variability Changes and Postoperative Delirium After Major Abdominal Surgery

NCT07783464 | Not Yet Recruiting

• 1 other identifier: 2026IIT-LX-0135
• Study Type: observational
• Target: 500
• Locations: 1 country
• Sites: 1

Brief 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. 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.

Conditions

Postoperative Delirium (POD); Heart Rate Variability (HRV)

Keywords

Postoperative delirium; Heart rate variability; Major abdominal surgery; Elderly patients

Outcome Measures

Primary Outcomes (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.

  Postoperative day 1 to postoperative day 7 after surgery

Secondary Outcomes (4)

• Severity of postoperative delirium

  Postoperative day 1 to postoperative day 7 after surgery

• Duration of postoperative delirium

  Postoperative day 1 to postoperative day 7 after surgery

• Change in cognitive function after surgery

  Postoperative day 7

• Quality of recovery after surgery

  Postoperative day 7

Study Arms (1)

Elderly Patients Undergoing Elective Major Abdominal Surgery

Elderly patients undergoing elective major abdominal surgery under general anesthesia will be prospectively enrolled and followed for postoperative delirium.

Other: Perioperative Heart Rate Variability Changes

Interventions

Perioperative Heart Rate Variability Changes OTHER

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.

Elderly Patients Undergoing Elective Major Abdominal Surgery

Eligibility Criteria

• Age: 65 Years - 85 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Older Adult (65+)
• Sampling Method: Non-Probability Sample

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.

You may qualify if:

• 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.

You may not qualify if:

• 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.
• 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.

Sponsors & Collaborators

• The First Affiliated Hospital with Nanjing Medical University: lead

Study Sites (1)

The First Affiliated Hospital with Nanjing Medical University

Nanjing, Jiangsu, 210029, China

Location

Related Publications (6)

• 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.

  PMID: 36081005 RESULT

• 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.

  PMID: 8598068 RESULT

• 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.

  PMID: 38703472 RESULT

• 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.

  PMID: 28742855 RESULT

• 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.

  PMID: 34135747 RESULT

• 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.

  PMID: 21658013 RESULT

MeSH Terms

Conditions

Emergence Delirium

Condition Hierarchy (Ancestors)

Delirium; Confusion; Neurobehavioral Manifestations; Neurologic Manifestations; Nervous System Diseases; Postoperative Complications; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Neurocognitive Disorders; Mental Disorders

Central Study Contacts

Junbei Wu

CONTACT

+86 13813955365; wujunbei88@sina.cn

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Chief Physician

Study Record Dates

• First Submitted: August 18, 2026
• First Posted: August 24, 2026
• Study Start (Estimated): September 1, 2026
• Primary Completion (Estimated): April 30, 2027
• Study Completion (Estimated): May 15, 2027
• Last Updated: August 27, 2026

Record last verified: 2026-08

Data Sharing

• IPD Sharing: Will not share

Locations

CN (1)