Perioperative EEG-Monitoring and Postoperative Delirium in Patients Undergoing Cardiovascular Surgery

Perioperative EEG-Monitoring and Postoperative Delirium in Patients Undergoing Cardiovascular Surgery: a Prospective Observational Study

Postoperative delirium is common in patients undergoing cardiovascular surgery and associated with poor outcomes. However the pathogenesis of postoperative delirium is poorly understood. Multichannel electroencephalogram is a recognized tool for identifying neurophysiologic states during anesthesia, sleep, and arousal. The aim of the current study is to evaluate the mechanisms and predictors of postoperative delirium in patients undergoing cardiovascular surgery using electroencephalogram.

Study Overview

• Status: Recruiting
• Conditions: Delirium

• Study Type: Observational
• Enrollment (Estimated): 200

Contacts and Locations

• Study Contact: Name: Hua Zheng, Dr.; Phone Number: 0086-27-83663173; Email: hzheng@hust.edu.cn

Study Locations

• China
  • Hubei
    • Wuhan, Hubei, China, 430030
      • Recruiting
      • Department of Anaesthesiology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology
      • Contact: Hua Zheng, Dr.

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Probability Sample

Study Population

Patients undergoing cardiovascular surgery

Description

Inclusion Criteria:

1. age of at least 18 years
2. normal cognitive function at the time of enrollment evidenced by a Mini-Mental State Examination (MMSE) score of more than 24 of 30
3. Chinese Mandarin as the native language
4. providing informed consent

Exclusion Criteria:

1. pre-existing delirium assessed according to the Confusion Assessment Method (CAM)
2. history of neurological or psychiatric disease
3. impaired vision or auditory function which may effect the assessments
4. unwillingness to participate in the study

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Delirium is determined by CAM or CAM-ICU score
No delirium is determined by CAM or CAM-ICU score

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of postoperative delirium	The incidence of postoperative delirium was determined according to the Confusion Assessment Method (CAM) diagnostic algorithm. The algorithm consists of four clinical criteria: (1) acute onset and fluctuating course, (2) inattention, (3) disorganized thinking, and (4) altered level of consciousness. To define a patient as having delirium, both the first and the second criteria have to be present, as well as either the third or the fourth criteria. The CAM-ICU will be used for patients who are intubated in the postoperative period.	After surgery through to postoperative day 7

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Relative power of each brain waves	Electroencephalogram data were acquired using a 32-channel electroencephalogram recording system (Brain Products, Germany). A 5 min, baseline, eyes-closed recording was conducted at the preoperative holding room when the patient was at rest. Recording of electroencephalogram was commenced before the start of anesthetic induction and was stopped before discharge of the patient from the operating room. We defied delta (1 to 3 Hz), theta (4 to 7 Hz), alpha (8 to 12 Hz), and beta (13 to 40 Hz) frequency bands. And then, the relative power of each frequency bands to the total power of the sum is calculated.	During the stay of the patient in the operating room, after surgery through to postoperative day 7
Duration of delirium		After surgery through to postoperative day 7
Severity of delirium	Delirium severity is evaluated both as the peak (highest) and sum Confusion Assessment Method - Severity (CAM-S) score over all hospital days. The CAM-S includes two forms: a Short Form (CAM-S Short Form, based on the 4-item algorithm, the sum of score ranging from 0 to 7, with 7 being the most severe) and a Long Form (CAM-S Long Form, based on the 10-item CAM instrument, the sum of score ranging from 0 to 19, with 19 being the most severe).	After surgery through to postoperative day 7
Worst daily pain scores at rest	Pain scores will be collected three times daily using a numeric rating scale (0, no pain, to 10, worst possible pain).	After surgery through to postoperative day 7
Worst daily pain scores with exertion (deep breathing and cough)	Pain scores will be collected three times daily using a numeric rating scale (0, no pain, to 10, worst possible pain).	After surgery through to postoperative day 7
Length of stay in the Intensive Care Unit (ICU)	Measured in days admitted in the ICU	through study completion, an average of 5 days
Length of hospital stay	Measured in days admitted in the hospital	through study completion, an average of 10 days

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Biomarkers	Identify biomarkers (such as Ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1), brain-derived neurotrophic factor (BDNF), and metalloproteases-9 (MMP-9) )of delirium and neural damage through changes in circulating plasma proteins and molecules	before and after surgery in operating room, after surgery through to postoperative day 7

Collaborators and Investigators

• Sponsor: Huazhong University of Science and Technology

Study record dates

Study Major Dates

• Study Start (Actual): June 17, 2021
• Primary Completion (Estimated): December 1, 2026
• Study Completion (Estimated): December 1, 2027

Study Registration Dates

• First Submitted: March 31, 2021
• First Submitted That Met QC Criteria: April 1, 2021
• First Posted (Actual): April 6, 2021

Study Record Updates

• Last Update Posted (Actual): March 31, 2026
• Last Update Submitted That Met QC Criteria: March 30, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Neurologic Manifestations; Nervous System Diseases; Mental Disorders; Confusion; Neurobehavioral Manifestations; Neurocognitive Disorders; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Delirium
• Other Study ID Numbers: TJMZK202101

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No