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Trial registered on ANZCTR


Registration number
ACTRN12617000533392
Ethics application status
Approved
Date submitted
1/06/2016
Date registered
12/04/2017
Date last updated
7/09/2021
Date data sharing statement initially provided
18/03/2019
Type of registration
Prospectively registered

Titles & IDs
Public title
What brain waves indicate conscious response during anaesthesia?
Scientific title
Electroencephalographic markers of behavioural responsiveness during anaesthesia in adults undergoing airway surgery
Secondary ID [1] 288926 0
None
Universal Trial Number (UTN)
U1111-1181-5561
Trial acronym
EMBRACE (Electroencephaolgraphic Markers of Behavioural Responsiveness during Anaesthesia: Consciousness Explored)
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Anaesthesia
Awareness
298265 0
Condition category
Condition code
Anaesthesiology 298408 298408 0 0
Other anaesthesiology
Neurological 302252 302252 0 0
Studies of the normal brain and nervous system

Intervention/exposure
Study type
Observational
Patient registry
False
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
Level of consciousness will be assessed using the behavioural response to the command ((patient name, if you can hear me, squeeze my hand)
The exposures will be slow intravenous induction of general anaesthesia, and then the steps involved in the airway surgery surgery itself, and then emergence from anaesthesia.
Behavioural responses will be checked at regular intervals throughout anaesthetic induction, surgery and emergence in conjunction with continuous multichannel EEG recording
Intervention code [1] 294390 0
Diagnosis / Prognosis
Comparator / control treatment
N/A
Control group
Uncontrolled

Outcomes
Primary outcome [1] 297880 0
EEG markers. Corresponding multichannel EEG epochs will be analysed for spectral measures, connectivity measures, entropy and other putative markers of consciousness/unconsciousness
Timepoint [1] 297880 0
EEG recordings will be continuous from induction of anaesthesia to emergence from anaesthesia. Specific epochs of interest will include:
Loss of consciousness
Surgical stimulation
Episodes of spontaneous movement
Return of consciousness
Secondary outcome [1] 324413 0
Composite autonomic responses (heart rate variability (from continuous ECG recordings) and galvanic skin responses (continuous sensor))
Timepoint [1] 324413 0
Continuous monitoring from induction of anaesthesia to emergence from anaesthesia
Secondary outcome [2] 333542 0
Behavioural response to verbal command by an observer ('X (patient's name), if you can hear me, squeeze my hand') assessed by observer noting whether or not their hand was squeezed
Timepoint [2] 333542 0
Verbal commands will be given throughout the induction of anaesthesia (every 30 seconds), maintenance(every 5 minutes) and emergence of anaesthesia (every 30 seconds).
Secondary outcome [3] 333692 0
Reflex motor responses to painful stimuli
Timepoint [3] 333692 0
There will be continuous observation for movements which could occur following any painful stimulus; an observer will record the time and a description of any movements observed
Secondary outcome [4] 345364 0
Implicit memory of verbal cues given at time of insertion of operating laryngoscope measured using the 2 Alternative Forced Choice Method
Timepoint [4] 345364 0
In the post-anaesthesia care unit

Eligibility
Key inclusion criteria
Adults undergoing airway surgery at Waikato Hospital
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Inability to provide informed consent
Inability to follow commands appropriately preoperatively

Study design
Purpose
Natural history
Duration
Cross-sectional
Selection
Convenience sample
Timing
Prospective
Statistical methods / analysis
Analysis will be done using MATLAB software. We shall be testing temporal and spatial EEG changes across transitions of responsiveness. We shall be making within and between individual comparisons to determine the most sensitive and specific EEG markers of unresponsiveness.
The number of participants required was calculated using findings from a volunteer study to guide the required sample size to achieve 80% power with alpha type 1 error risk 0.05 for paired t-test comparisons of a EEG coherence measure across transitions of consciousness. We increased sample size over and above the minimum suggested by these calculations to account for a more heterogeneous study population and less tightly controlled anaesthetic regime

Recruitment
Recruitment status
Recruiting
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment outside Australia
Country [1] 7769 0
New Zealand
State/province [1] 7769 0
Waikato

Funding & Sponsors
Funding source category [1] 293272 0
Hospital
Name [1] 293272 0
Waikato Hospital
Country [1] 293272 0
New Zealand
Funding source category [2] 296100 0
Other
Name [2] 296100 0
Australian and New Zealand College of Anaesthetists
Country [2] 296100 0
Australia
Primary sponsor type
Hospital
Name
Waikato Hospital Dept of Anaesthesia
Address
Selwyn Street and Pembroke Street, Waikato Hospital, Hamilton 3204
Country
New Zealand
Secondary sponsor category [1] 294998 0
None
Name [1] 294998 0
Address [1] 294998 0
Country [1] 294998 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 294750 0
Southern Health and Disabilty Ethics Committee
Ethics committee address [1] 294750 0
Ethics committee country [1] 294750 0
New Zealand
Date submitted for ethics approval [1] 294750 0
18/04/2016
Approval date [1] 294750 0
28/09/2016
Ethics approval number [1] 294750 0
16/STH/134

Summary
Brief summary
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 64934 0
Dr Amy Gaskell
Address 64934 0
Dept of Anaesthesia
Waikato Hospital
Private Bag 3200
Corner Pembroke Selwyn St
Hamilton
3204
Country 64934 0
New Zealand
Phone 64934 0
+64 78398899
Fax 64934 0
+64 7 8398761
Email 64934 0
Contact person for public queries
Name 64935 0
Amy Gaskell
Address 64935 0
Dept of Anaesthesia
Waikato Hospital
Private Bag 3200
Corner Pembroke Selwyn St
Hamilton
3204
Country 64935 0
New Zealand
Phone 64935 0
+64 78398899
Fax 64935 0
+64 7 8398761
Email 64935 0
Contact person for scientific queries
Name 64936 0
Amy Gaskell
Address 64936 0
Dept of Anaesthesia
Waikato Hospital
Private Bag 3200
Corner Pembroke Selwyn St
Hamilton
Country 64936 0
New Zealand
Phone 64936 0
+64 7 8398899
Fax 64936 0
+64 7 8398761
Email 64936 0

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.