General Anesthesia-Induced Altered ConsciousnessPhase 4NCT07836205
Brain Activity and Changes in Consciousness During General Anesthesia
A Phase 4 study testing Propofol (Group P), Remimazolam group and Esketamine group in people with General Anesthesia-Induced Altered Consciousness, run by Beijing Chao Yang Hospital at 1 site in China.
Trial summary
This study aims to investigate how general anesthetics alter brain activity and consciousness across different age groups. The study will evaluate four anesthetic agents with different mechanisms of action: propofol, remimazolam, esketamine, and dexmedetomidine. Read more about this study
- Who is it for?
- Ages 6 to 80 yearsHealthy volunteers can take part
- Conditions the study is for
- General Anesthesia-Induced Altered Consciousness
- What is being tested?
- Propofol (Group P), Remimazolam group and Esketamine group
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 320 participants
- Where
- 1 siteChina
- Study dates
- Sep 2026to Dec 2028
- Phase
- Phase 4
- 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 6 to 80 years
- All sexes
- Healthy volunteers accepted
- Child, Adult, Older adult
Who may be able to join
- Participants must belong to one of the following prespecified age groups: children aged 6-12 years, young adults aged 20-40 years, or older adults aged 65-80 years.
- Children must be surgical patients undergoing general anesthesia. Young adult and older adult participants will be healthy volunteers.
- American Society of Anesthesiologists (ASA) physical status I; older adult participants may have ASA physical status II.
- Written informed consent must be obtained from all adult participants and surgical patients as applicable. For pediatric participants, written informed consent must be provided by a parent or legal guardian.
Who cannot join
- History of neuropsychiatric disorders, including epilepsy, dementia, or other relevant neurological or psychiatric diseases.
- Known hearing impairment or physical impairment that may interfere with completion of the study procedures or tasks.
- History of allergy to propofol, benzodiazepines, or other anesthetic agents used in the study.
- Long-term use of sedative or analgesic medications for more than 1 month. Disturbed sleep pattern within 14 days before the study, including shift work or insomnia.
- Communication difficulties or inability to cooperate with EEG data acquisition.
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
Affiliated Beijing Chaoyang Hospital of Capital Medical University
Beijing, 100020
Wei, +86 13810678936, changwei.wei@ccmu.edu.cn
About this study
Official title: Mechanism Exploration of General Anesthesia-Induced Altered Consciousness Via Cortical-Thalamic Network Modulation and Development of a Precision Anesthesia Depth Monitoring Device
This study aims to investigate how general anesthetics alter brain activity and consciousness across different age groups. The study will evaluate four anesthetic agents with different mechanisms of action: propofol, remimazolam, esketamine, and dexmedetomidine. Electroencephalography (EEG) will be recorded during wakefulness, anesthetic induction, loss of responsiveness, and recovery of responsiveness to characterize changes in brain activity and brain network dynamics.
The study includes children aged 6-12 years undergoing surgery, healthy young adults aged 20-40 years, and healthy older adults aged 65-80 years. Resting-state EEG will be used to examine changes in brain rhythms, temporal and spatial brain dynamics, and network organization across different levels of consciousness. In a subgroup of young adult participants, auditory stimuli will also be presented continuously to investigate how the brain processes sounds and meaningful information as consciousness decreases and subsequently recovers.
The study will compare EEG changes across anesthetic agents, age groups, and states of consciousness. It will also evaluate the timing of loss and recovery of responsiveness, anesthetic dose-response relationships, and adverse events. The overall goal is to identify brain activity patterns associated with anesthesia-induced changes in consciousness and to provide a scientific basis for improved monitoring of consciousness and anesthetic depth.
- Being tested
- Propofol (Group P), Remimazolam group, Esketamine group, Dexmedetomidine group
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Propofol (Group P)Drug
Propofol will be administered by target-controlled infusion in young and older healthy volunteers. The plasma target concentration will be increased by 0.5 μg/mL every 5 minutes, up to a maximum of 5 μg/mL, until protocol-defined loss of responsiveness is achieved. Consciousness will be assessed every minute using the Modified Observer's Assessment of Alertness/Sedation (MOAA/S) scale, and EEG will be recorded throughout anesthetic induction and recovery.
Remimazolam groupDrug
Remimazolam will be administered intravenously in young and older healthy volunteers at sequential infusion rates of 0.5, 1.0, 1.5, and 2.0 mg/kg/h, with each level maintained for 5 minutes, until protocol-defined loss of responsiveness is achieved. Consciousness will be assessed every minute using the Modified Observer's Assessment of Alertness/Sedation (MOAA/S) scale, and EEG will be recorded throughout anesthetic induction and recovery.
Esketamine groupDrug
Esketamine will be administered intravenously in young and older healthy volunteers. The infusion rate will be increased by 0.10 mg/kg/h every 5 minutes, up to a maximum of 0.50 mg/kg/h, until protocol-defined loss of responsiveness is achieved. Consciousness will be assessed every minute using the Modified Observer's Assessment of Alertness/Sedation (MOAA/S) scale, and EEG will be recorded throughout anesthetic induction and recovery.
Dexmedetomidine groupDrug
Dexmedetomidine will be administered intravenously in young and older healthy volunteers with stepwise increases in the infusion rate of 0.1 μg/kg/h, up to a maximum of 0.7 μg/kg/h, until protocol-defined loss of responsiveness is achieved. Consciousness will be assessed every minute using the Modified Observer's Assessment of Alertness/Sedation (MOAA/S) scale, and EEG will be recorded throughout anesthetic induction and recovery.
| Study group | Role | What they receive |
|---|---|---|
| Propofol Group | Experimental | Participants in this arm will receive propofol. In young and older healthy volunteers, propofol will be administered by target-controlled infusion, with the plasma target concentration increased by 0.5 μg/mL every 5 minutes up to a maximum of 5 μg/mL to induce loss of responsiveness. EEG will be recorded during wakefulness, anesthetic induction, loss of responsiveness, and recovery. Pediatric surgical participants in this group will undergo EEG recording during anesthesia in the operating room. Receives: Drug: Propofol (Group P) |
| Remimazolam Group | Experimental | Participants in this arm will receive remimazolam. In young and older healthy volunteers, remimazolam will be administered intravenously at sequential infusion rates of 0.5, 1.0, 1.5, and 2.0 mg/kg/h, with each level maintained for 5 minutes, until loss of responsiveness is achieved. EEG will be recorded during wakefulness, anesthetic induction, loss of responsiveness, and recovery. Pediatric surgical participants in this group will undergo EEG recording during anesthesia in the operating room. Receives: Drug: Remimazolam group |
| Esketamine Group | Experimental | Participants in this arm will receive esketamine. In young and older healthy volunteers, esketamine will be administered intravenously with the infusion rate increased by 0.10 mg/kg/h every 5 minutes, up to a maximum of 0.50 mg/kg/h, to induce loss of responsiveness. EEG will be recorded during wakefulness, anesthetic induction, loss of responsiveness, and recovery. Pediatric surgical participants in this group will undergo EEG recording during anesthesia in the operating room. Receives: Drug: Esketamine group |
| Dexmedetomidine Group | Experimental | Participants in this arm will receive dexmedetomidine. In young and older healthy volunteers, dexmedetomidine will be administered intravenously with stepwise increases of 0.1 μg/kg/h, up to a maximum of 0.7 μg/kg/h, to induce loss of responsiveness. EEG will be recorded during wakefulness, anesthetic induction, loss of responsiveness, and recovery. Pediatric surgical participants in this group will undergo EEG recording during anesthesia in the operating room. Receives: Drug: Dexmedetomidine group |
What is being measured
The primary outcome is the main question the study is designed to answer.
Changes in Resting-State Quantitative EEG Measures Across Behavioral Responsiveness States
Continuous resting-state EEG will be quantified across awake baseline, anesthetic induction, loss of responsiveness, maintenance, emergence, and recovery. Prespecified measures include delta power (0.5-4 Hz), alpha power (8-12 Hz), theta/alpha power ratio, slow-wave index (SWI), burst suppression ratio (BSR), autocorrelation window at the first zero crossing (ACW-0), EEG complexity (gMLZC), and alpha-band (8-13 Hz) functional connectivity/network measures, including wPLI/dwPLI² and weighted global efficiency. Each measure will be analyzed separately.
Measured: From the start of the 10-minute awake baseline through anesthetic induction, loss-of-responsiveness maintenance, emergence, and 30 minutes after recovery of responsiveness
Changes in Auditory-Evoked ERP and Time-Frequency EEG Measures Across Behavioral Responsiveness States
Auditory-evoked EEG will be quantified across awake baseline, anesthetic induction, loss of responsiveness, maintenance, emergence, and recovery. Event-related potential (ERP) measures include N100, mismatch negativity (MMN), N400, and P300 amplitudes and their state-related temporal dynamics. Stimuli include pure tones, white noise, characters, words, sentences, another person's name, and the participant's own name. Time-frequency measures include event-related theta-band activity (4-8 Hz), alpha-band activity (8-12 Hz), and intertrial phase coherence. Source-space analyses will localize N400 and P300 generators, and single-trial ERP amplitudes will be analyzed in relation to behavioral responsiveness. Each measure will be analyzed separately.
Measured: From the start of the 10-minute awake baseline through anesthetic induction, loss of responsiveness, maintenance, emergence, and at least 10 minutes after recovery of responsiveness
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Sep 2026
- Study startSep 2026 (estimated)
- Primary completionSep 2028 (estimated)
- Study completionDec 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for General Anesthesia-Induced Altered ConsciousnessStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 320 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Beijing Chao Yang Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07836205
- Sponsor's protocol ID
- 2026-ke-429
- Other IDs
- L2510005
- Status last verified
- Aug 2026
- First submitted
- 4 Sep 2026
- Last updated
- 23 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 23 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Mechanism Exploration of General Anesthesia-Induced Altered Consciousness Via Cortical-Thalamic Network Modulation and Development of a Precision Anesthesia Depth Monitoring Device
- ClinicalTrials.gov ID
- NCT07836205
- Acronym / sponsor ID
- 2026-ke-429
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 320 participants (estimated)
- Lead sponsor
- Beijing Chao Yang HospitalUniversity, hospital or other
- Study start
- Sep 2026 (estimated)
- Primary completion
- Sep 2028 (estimated)
- Study completion
- Dec 2028 (estimated)
- First posted
- 23 Sep 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study aims to investigate how general anesthetics alter brain activity and consciousness across different age groups. The study will evaluate four anesthetic agents with different mechanisms of action: propofol, remimazolam, esketamine, and dexmedetomidine. Electroencephalography (EEG) will be recorded during wakefulness, anesthetic induction, loss of responsiveness, and recovery of responsiveness to characterize changes in brain activity and brain network dynamics.
The study includes children aged 6-12 years undergoing surgery, healthy young adults aged 20-40 years, and healthy older adults aged 65-80 years. Resting-state EEG will be used to examine changes in brain rhythms, temporal and spatial brain dynamics, and network organization across different levels of consciousness. In a subgroup of young adult participants, auditory stimuli will also be presented continuously to investigate how the brain processes sounds and meaningful information as consciousness decreases and subsequently recovers.
The study will compare EEG changes across anesthetic agents, age groups, and states of consciousness. It will also evaluate the timing of loss and recovery of responsiveness, anesthetic dose-response relationships, and adverse events. The overall goal is to identify brain activity patterns associated with anesthesia-induced changes in consciousness and to provide a scientific basis for improved monitoring of consciousness and anesthetic depth.
Study design
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Propofol Group | Experimental | Drug: Propofol (Group P)Participants in this arm will receive propofol. In young and older healthy volunteers, propofol will be administered by target-controlled infusion, with the plasma target concentration increased by 0.5 μg/mL every 5 minutes up to a maximum of 5 μg/mL to induce loss of responsiveness. EEG will be recorded during wakefulness, anesthetic induction, loss of responsiveness, and recovery. Pediatric surgical participants in this group will undergo EEG recording during anesthesia in the operating room. |
| Remimazolam Group | Experimental | Drug: Remimazolam groupParticipants in this arm will receive remimazolam. In young and older healthy volunteers, remimazolam will be administered intravenously at sequential infusion rates of 0.5, 1.0, 1.5, and 2.0 mg/kg/h, with each level maintained for 5 minutes, until loss of responsiveness is achieved. EEG will be recorded during wakefulness, anesthetic induction, loss of responsiveness, and recovery. Pediatric surgical participants in this group will undergo EEG recording during anesthesia in the operating room. |
| Esketamine Group | Experimental | Drug: Esketamine groupParticipants in this arm will receive esketamine. In young and older healthy volunteers, esketamine will be administered intravenously with the infusion rate increased by 0.10 mg/kg/h every 5 minutes, up to a maximum of 0.50 mg/kg/h, to induce loss of responsiveness. EEG will be recorded during wakefulness, anesthetic induction, loss of responsiveness, and recovery. Pediatric surgical participants in this group will undergo EEG recording during anesthesia in the operating room. |
| Dexmedetomidine Group | Experimental | Drug: Dexmedetomidine groupParticipants in this arm will receive dexmedetomidine. In young and older healthy volunteers, dexmedetomidine will be administered intravenously with stepwise increases of 0.1 μg/kg/h, up to a maximum of 0.7 μg/kg/h, to induce loss of responsiveness. EEG will be recorded during wakefulness, anesthetic induction, loss of responsiveness, and recovery. Pediatric surgical participants in this group will undergo EEG recording during anesthesia in the operating room. |
Who may qualify
- Ages
- 6 to 80 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (4 listed)
- Participants must belong to one of the following prespecified age groups: children aged 6-12 years, young adults aged 20-40 years, or older adults aged 65-80 years.
- Children must be surgical patients undergoing general anesthesia. Young adult and older adult participants will be healthy volunteers.
- American Society of Anesthesiologists (ASA) physical status I; older adult participants may have ASA physical status II.
- Written informed consent must be obtained from all adult participants and surgical patients as applicable. For pediatric participants, written informed consent must be provided by a parent or legal guardian.
Key exclusion criteria (5 listed)
- History of neuropsychiatric disorders, including epilepsy, dementia, or other relevant neurological or psychiatric diseases.
- Known hearing impairment or physical impairment that may interfere with completion of the study procedures or tasks.
- History of allergy to propofol, benzodiazepines, or other anesthetic agents used in the study.
- Long-term use of sedative or analgesic medications for more than 1 month. Disturbed sleep pattern within 14 days before the study, including shift work or insomnia.
- Communication difficulties or inability to cooperate with EEG data acquisition.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Propofol (Group P)Propofol will be administered by target-controlled infusion in young and older healthy volunteers. The plasma target concentration will be increased by 0.5 μg/mL every 5 minutes, up to a maximum of 5 μg/mL, until protocol-defined loss of responsiveness is achieved. Consciousness will be assessed every minute using the Modified Observer's Assessment of Alertness/Sedation (MOAA/S) scale, and EEG will be recorded throughout anesthetic induction and recovery. | Drug | Propofol Group |
| Remimazolam groupRemimazolam will be administered intravenously in young and older healthy volunteers at sequential infusion rates of 0.5, 1.0, 1.5, and 2.0 mg/kg/h, with each level maintained for 5 minutes, until protocol-defined loss of responsiveness is achieved. Consciousness will be assessed every minute using the Modified Observer's Assessment of Alertness/Sedation (MOAA/S) scale, and EEG will be recorded throughout anesthetic induction and recovery. | Drug | Remimazolam Group |
| Esketamine groupEsketamine will be administered intravenously in young and older healthy volunteers. The infusion rate will be increased by 0.10 mg/kg/h every 5 minutes, up to a maximum of 0.50 mg/kg/h, until protocol-defined loss of responsiveness is achieved. Consciousness will be assessed every minute using the Modified Observer's Assessment of Alertness/Sedation (MOAA/S) scale, and EEG will be recorded throughout anesthetic induction and recovery. | Drug | Esketamine Group |
| Dexmedetomidine groupDexmedetomidine will be administered intravenously in young and older healthy volunteers with stepwise increases in the infusion rate of 0.1 μg/kg/h, up to a maximum of 0.7 μg/kg/h, until protocol-defined loss of responsiveness is achieved. Consciousness will be assessed every minute using the Modified Observer's Assessment of Alertness/Sedation (MOAA/S) scale, and EEG will be recorded throughout anesthetic induction and recovery. | Drug | Dexmedetomidine Group |
Primary outcome
Changes in Resting-State Quantitative EEG Measures Across Behavioral Responsiveness States
Time frame: From the start of the 10-minute awake baseline through anesthetic induction, loss-of-responsiveness maintenance, emergence, and 30 minutes after recovery of responsiveness
Continuous resting-state EEG will be quantified across awake baseline, anesthetic induction, loss of responsiveness, maintenance, emergence, and recovery. Prespecified measures include delta power (0.5-4 Hz), alpha power (8-12 Hz), theta/alpha power ratio, slow-wave index (SWI), burst suppression ratio (BSR), autocorrelation window at the first zero crossing (ACW-0), EEG complexity (gMLZC), and alpha-band (8-13 Hz) functional connectivity/network measures, including wPLI/dwPLI² and weighted global efficiency. Each measure will be analyzed separately.
Changes in Auditory-Evoked ERP and Time-Frequency EEG Measures Across Behavioral Responsiveness States
Time frame: From the start of the 10-minute awake baseline through anesthetic induction, loss of responsiveness, maintenance, emergence, and at least 10 minutes after recovery of responsiveness
Auditory-evoked EEG will be quantified across awake baseline, anesthetic induction, loss of responsiveness, maintenance, emergence, and recovery. Event-related potential (ERP) measures include N100, mismatch negativity (MMN), N400, and P300 amplitudes and their state-related temporal dynamics. Stimuli include pure tones, white noise, characters, words, sentences, another person's name, and the participant's own name. Time-frequency measures include event-related theta-band activity (4-8 Hz), alpha-band activity (8-12 Hz), and intertrial phase coherence. Source-space analyses will localize N400 and P300 generators, and single-trial ERP amplitudes will be analyzed in relation to behavioral responsiveness. Each measure will be analyzed separately.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Sep 2026.
- Individual participant dataSharing planned: Undecided
Related trials for General Anesthesia-Induced Altered Consciousness
RecruitingObservational study
Correlating EEG Dynamics With Consciousness Alteration Under Anesthesia
Altered State of Consciousness, General Anesthetics
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Propofol (Group P), Remimazolam group and Esketamine group in people with General Anesthesia-Induced Altered Consciousness, run by Beijing Chao Yang Hospital 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 4 inclusion and 5 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: opening soon, as of the sponsor's last update on 23 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.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
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 Wei (+86 13810678936, changwei.wei@ccmu.edu.cn), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Changes in Resting-State Quantitative EEG Measures Across Behavioral Responsiveness States (time frame: From the start of the 10-minute awake baseline through anesthetic induction, loss-of-responsiveness maintenance, emergence, and 30 minutes after recovery of responsiveness). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 23 Sep 2026.