General anaesthesia Surgery
Conditions
Interventions
Patient study - Study 1
This study will be performed in up to 30 patients who are having general anaesthesia for elective plastic surgery in the Oxford University Hospitals (OUH) NHS Foundation Trust.
Sponsors
University of Oxford
Eligibility
Sex/Gender
All
Inclusion criteria
Inclusion criteria: All study participants will be required to meet the inclusion criteria outlined below: 1. Willing and able to give informed consent 2. Aged 18-60 years 3. American Society of Anesthesiology (ASA) score of 1 or 2 4. English-speaking
Exclusion criteria
Exclusion criteria: For all participants: 1. Smoker (tobacco or electronic cigarettes) 2. Illicit drug use 3. High alcohol intake (>14 units/week) 4. Pregnancy 5. Prescription medication that could influence the EEG or interact with anaesthesia 6. Personal or familial history of allergies and/or adverse reactions to anaesthesia 7. History or clinical signs of potential susceptibility to airway obstruction, and known difficult airway 8. Personal or familial history of epilepsy, other neurological disorder or psychiatric disorder 9. History of psychological pathology, chronic pain, migraines or dementia 10. Increased risk of venous thrombo-embolic event (VTE), defined by: 10.1. Obesity (body mass index >30 kg/m2) 10.2. Personal history or first-degree relative with a history of VTE 10.3. Use of hormone replacement therapy 11. Vulnerable group status: 11.1. Drug, alcohol or substance abuse issues 11.2. Learning difficulties 11.3. Difficulty reading or speaking English 11.4. Homeless, asylum seekers/refugees or those with no recourse to public funds 11.5. In contact with prison or probation services For patients undergoing surgery (Study 1): 12. Surgery involving the head or neck, or the prone position 13. Patients involved in litigation cases 14. Other surgical reason at the research or clinical team’s discretion For healthy volunteers (Study 2): 15. Left-handed 16. Claustrophobia 17. Certain metallic implants 18. Metallic injury to eye 19. Tattoos (depending on location)
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Resting and functional thalamocortical connectivity at loss of behavioural responsiveness (LOBR) and slow wave activity saturation (SWAS) assessed by fMRI | — |
Secondary
| Measure | Time frame |
|---|---|
| 1. Achievement of stable SWAS within 15 min assessed using EEG 2. Response to pain of individuals held at SWAS assessed by the isolated forearm test 3. Behavioural response (as assessed by hand open/close) to verbal request when held at SWAS 4. EEG power at SWAS under anaesthesia assessed using EEG 5. Maximum EEG power observed during slow-wave sleep assessed using EEG | — |
Countries
England, United Kingdom
Outcome results
None listed