Neuro-Mimic Indicators of Anesthesia Depth During General Anesthesia

NCT07199049 | Not Yet Recruiting

• 1 other identifier: NEURO3419
• Study Type: observational
• Target: 60
• Locations: 0 countries
• Sites: N/A

Brief Summary

This prospective observational study will evaluate neuro-mimic indicators of anesthesia depth, including eyelid reflex, eyeball movements, and pupil responses, in patients undergoing elective surgery under general anesthesia. Sixty adult patients will be observed at three standardized time points: after induction, during skin incision, and mid-surgery. All parameters will be recorded alongside bispectral index (BIS) monitoring. The study aims to determine whether these observable signs correlate with anesthesia depth, contribute to early detection of intraoperative awareness, and provide a basis for developing non-invasive depth monitoring systems.

Conditions

General Anesthesia; Intraoperative Awareness; Eye Movements

Keywords

Anesthesia, General; Awareness, Intraoperative; Pupillary Reflex; Eye Movements; Reflex, Blink (Eyelid Reflex)

Outcome Measures

Primary Outcomes (1)

• Change in pupil diameter during general anesthesia

  Pupil diameter (mm) will be measured and compared at three intraoperative stages: after induction and intubation, during skin incision, and mid-surgery. The change over time will be analyzed as an indicator of anesthesia depth.

  Intraoperative period (observations at induction, incision, and mid-surgery).

Secondary Outcomes (4)

• Presence or absence of eyelid reflex at different anesthesia stages

  Intraoperative period (induction, incision, mid-surgery).

• Eye position and movements during anesthesia

  Intraoperative period (induction, incision, mid-surgery).

• Correlation of neuro-mimic indicators with BIS values

  Intraoperative period (induction, incision, mid-surgery).

• Early indicators of intraoperative awareness

  Intraoperative period.

Interventions

Neuro-Mimic Observation Protocol OTHER

Observation of eyelid reflex, eye movements, and pupil responses at three standardized intraoperative time points (after induction, during skin incision, and mid-surgery). Parameters will be recorded alongside BIS values without any intervention, device application, or additional risk to patients.

Also known as: Eyelid Reflex Monitoring, Eye Movement Observation, Pupil Diameter Assessment

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Adult patients aged 18-65 years, ASA physical status I-III, undergoing elective abdominal surgery under general anesthesia at Başakşehir Çam and Sakura City Hospital will be included. Eligible patients must have the eye area uncovered and in a position suitable for observation, with surgery expected to last 1-3 hours. Both male and female patients will be enrolled. Head, neck, and eye surgeries or cases requiring full draping of the eye area will be excluded.

You may qualify if:

• The study will include patients aged 18-65 who will undergo elective abdominal surgery (e.g., cholecystectomy/gastrectomy/colorectal surgery/prostatectomy/hysterectomy, etc.) under general anesthesia, with a planned duration of 1-3 hours.
• Patients whose eye area is left uncovered and who are in a position suitable for observation
• Patients who have signed the informed consent form
• Patients with an ASA score of I-III

You may not qualify if:

• Patients undergoing surgical procedures in the head, neck, or face region (e.g., ENT, eye, jaw surgery, neurosurgery, thyroid/parathyroid)
• Patients whose eye area must be completely covered with a sterile drape
• Patients with an ASA score of IV or higher
• Individuals with neurological disorders and impaired pupil response, patients who have previously undergone eye trauma or surgery and cannot undergo pupil evaluation
• Patients who are unable to communicate and cannot provide informed consent
• Emergency surgeries (e.g., appendectomy/ileus/gastrointestinal perforation/cesarean section/gunshot wounds/stab wounds/multiple trauma/traffic accidents, etc.)

Sponsors & Collaborators

• Başakşehir Çam & Sakura City Hospital: lead

Related Publications (4)

• Ben Barak-Dror O, Hadad B, Barhum H, Haggiag D, Tepper M, Gannot I, Nir Y. Touchless short-wave infrared imaging for dynamic rapid pupillometry and gaze estimation in closed eyes. Commun Med (Lond). 2024 Aug 6;4(1):157. doi: 10.1038/s43856-024-00572-1.

  PMID: 39107497 BACKGROUND

• Singh A, Akhileshwar, Kumar N, De RR, Bahadur R, Shekhar S. The Role of Pupillometry in the Assessment of Pain in Children Under General Anesthesia: A Prospective Single-Blinded Observational Study. Cureus. 2023 Aug 22;15(8):e43894. doi: 10.7759/cureus.43894. eCollection 2023 Aug.

  PMID: 37753025 BACKGROUND

• Chaurasia S, Soni SL, Ganesh V, Ram J, Sukhija J, Chaurasia S, Takkar A. Tonic down-rolling and eccentric down-positioning of eyes under sevoflurane anesthesia without non-depolarizing muscle relaxant and its relationship with depth of anesthesia. Front Med (Lausanne). 2023 Jun 15;10:1029952. doi: 10.3389/fmed.2023.1029952. eCollection 2023.

  PMID: 37396902 BACKGROUND

• Xing L, Xie H, Zhou X, Zhu J, Liu H. Ultrasound Measurement of Pupillary Dilation Reflex During Induction of General Anesthesia Using Sufentanil: A Randomized Controlled Trial. Med Sci Monit. 2025 Jun 23;31:e948209. doi: 10.12659/MSM.948209.

  PMID: 40549665 BACKGROUND

MeSH Terms

Conditions

Intraoperative Awareness

Interventions

Eye Movements

Condition Hierarchy (Ancestors)

Intraoperative Complications; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena; Ocular Physiological Phenomena

Study Officials

• Emine Ozcan, MD

  Başakşehir Çam & Sakura City Hospital

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Emine Ozcan, MD

CONTACT

+905301592856; dr.emine3419@gmail.com

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER GOV
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: September 22, 2025
• First Posted: September 30, 2025
• Study Start: February 3, 2026
• Primary Completion (Estimated): July 25, 2026
• Study Completion (Estimated): July 28, 2026
• Last Updated: February 5, 2026

Record last verified: 2026-02

Data Sharing

• IPD Sharing: Will not share