Perioperative EEG variability and risk of postoperative delirium

Correlation Between Multiscale Entropy Analysis of Electroencephalograms and Postoperative Delirium Incidence.

This study will see if patterns in EEG recordings before and during surgery can identify older patients at risk for postoperative delirium.

Quick facts

• Study type: Observational
• Enrollment: 90 (estimated)
• Ages: 65 Years and up
• Sex: All
• Sponsor: Hainan Medical College (Academic / other)
• Locations: 1 site (Haikou)
• Trial ID: NCT07323940 on ClinicalTrials.gov

What this trial studies

This observational study records preoperative and intraoperative electroencephalogram (EEG) data from patients aged 65 and older undergoing general anesthesia with a single-lumen endotracheal tube. Multiscale entropy analysis will be applied to EEG signals to compare temporal complexity between patients who develop postoperative delirium and those who do not. Key exclusions include severe organ dysfunction, psychiatric or communication barriers, cardiac or neurosurgical procedures, recent sedative or opioid use, low hemoglobin, and recent participation in other clinical research. The aim is to find EEG-based signatures that could enable earlier recognition of postoperative delirium.

Who should consider this trial

Good fit: Ideal candidates are patients aged 65 or older having surgery under general anesthesia with a single-lumen endotracheal tube, BMI 18–28 kg/m², ASA I–II, Mallampati I–II, and able to cooperate with delirium screening.

Not a fit: Patients with severe organ disease, psychiatric or communication barriers, those undergoing cardiac or neurosurgery, recent sedative or opioid use, low hemoglobin, or recent trial participation are unlikely to benefit from this protocol.

Why it matters

Potential benefit: If successful, this approach could enable earlier detection of delirium after surgery and prompt interventions to reduce complications and length of stay.

How similar studies have performed: Some prior research has linked EEG complexity measures to delirium risk, but using multiscale entropy perioperatively as a practical screening tool remains exploratory.

Eligibility criteria

Inclusion Criteria:

1. Patients undergoing general anaesthesia with single-lumen endotracheal tube placement;
2. Age ≥65 years, gender unrestricted, body mass index (BMI) 18-28 kg/m²;
3. Normal mouth opening and head/neck mobility;
4. Pre-anaesthesia American Society of Anaesthesiologists (ASA) physical status classification of I or II and Mallampati airway classification of I or II.

Exclusion Criteria:

1. Individuals with psychiatric disorders, literacy issues, or communication difficulties who are unable to cooperate with POD screening;
2. Patients with severe lesions in vital organs, such as the heart, lungs, brain, liver or kidneys.
3. Those undergoing cardiac or neurosurgical procedures during this admission;
4. A history of alcohol abuse or recent use of sedatives or opioids;
5. haemoglobin \<100 g/L;
6. Participation in any clinical research studies within the past 3 months.

Where this trial is running

Haikou

• Department of Anesthesiology,the Second Affiliated Hospital of Hainan Medical University — Haikou, China (Recruiting)

Study contacts

• Study coordinator: Fu Dr.chen

Conditions Delirium - Postoperative; Postoperative delirium; electroencephalogram; Multiscale Entropy