Anaesthetic depth and delirium after major surgery: a randomised clinical trial.
Lisbeth A Evered, Matthew T V Chan, Ruquan Han...
https://pubmed.ncbi.nlm.nih.gov/34465469Actively Recruiting
Phase Not Applicable
Age: 55Years +
All Genders
ID06268080
Preserving Brain Health After Surgery: Does Light General Anesthesia Reduce Postoperative Delirium and Cognitive Decline Compared With Deep General Anesthesia in Older Adults?
Led by Auckland City Hospital · Updated on 2025-09-25
2766
Participants Needed
3
Research Sites
52 weeks
Total Duration
On this page
AI-Summary
What this Trial Is About
Researchers are studying the effects of light versus deep general anesthesia in older adults undergoing major surgery to see if lighter anesthesia can reduce postoperative delirium, cognitive decline, and disability. Delirium is a common and serious complication in older surgical patients, causing distress and long-term health issues. This trial targets older adults aged 65 and above, including Indigenous and Pacific patients aged 55 and above, undergoing non-heart and non-brain major surgery under total intravenous anesthesia (TIVA). Participants will be randomly assigned to two groups receiving either light or deep general anesthesia guided by processed electroencephalography (pEEG) brain monitors, such as the Bispectral Index (BIS) or Patient State Index (PSI). The anesthesiologist will adjust anesthetic drugs based on brain wave readings from 10 minutes after anesthesia induction until awakening. The study limits certain drugs that interfere with brain monitoring. Care during surgery follows standard protocols except for the anesthesia depth adjustment. During the study, participants will be assessed twice daily for up to three days after surgery to detect delirium and monitored further if delirium occurs. Longer-term follow-ups at 90 days and one year will evaluate cognitive, physical function, and survival outcomes. The study aims to understand if anesthesia depth affects delirium rates and longer-term brain health, with careful tracking of participant health and safety throughout the process.
CONDITIONS
Brief Title
Depth of Anesthesia on Postoperative Delirium and Cognitive After Surgery
Who Can Participate
Age: 55Years +
All Genders
Eligibility Criteria
You may qualify if you...
- Patients aged 65 years or older, or Māori, Pacific, or Indigenous patients aged 55 years or older
- Undergoing major elective or non-elective surgery expected to last at least 2 hours
- Expected postoperative hospital stay of at least 2 nights
- Receiving general anesthesia using total intravenous anesthesia (TIVA) with brain monitoring (pEEG)
- Able to provide informed consent, including those with mild preoperative cognitive disorders
You will not qualify if you...
- Undergoing intracranial or cardiac surgery
- Surgery requiring a 'wake up' test
- Previous participation in the Balanced-2 study
- Terminal illness with expected survival less than 3 months
- Emergency surgery within 6 hours of hospital presentation
- Cognitive impairment preventing informed consent or requiring activated power of attorney
- Clinically impaired due to acute illness or preoperative delirium preventing consent
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
1
2
3
Your Study Journey
Screening
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 visit (in-person)
Surgery and Immediate Post-operative Care
Duration - Surgery day and hospital stay of at least 2 nights
Participants undergo major surgery with general anesthesia titrated to a light or deep level using brain monitoring devices. Anesthesia is maintained from 10 minutes after induction until emergence.
Daily assessments twice a day for up to 3 days post-surgery, with additional daily testing on days 4 to 7 if delirium is detected
Post-operative Follow-up
Duration - Up to 1 year after surgery
Participants are assessed for cognitive, functional, and delirium outcomes after surgery to monitor recovery and long-term effects.
Assessments at 90 days and 1 year after surgery
Trial Site Locations
Total: 3 locations
1
Auckland City Hospital, Health New Zealand
Grafton, Auckland, New Zealand, 1024
Actively Recruiting
2
North Shore Hospital
Auckland, North Island, New Zealand, 0622
Not Yet Recruiting
3
Christchurch Hospital
Christchurch, South Island, New Zealand, 4710
Actively Recruiting
Loading map...
Research Team
D
Davina J McAllister, DipNursing
C
Carolyn Deng
How is the study designed?
Study Type
INTERVENTIONAL
Masking
TRIPLE
Allocation
RANDOMIZED
Model
PARALLEL
Primary Purpose
PREVENTION
Number of Arms
2
Similar Trials
Frequently Asked Questions
Have more questions? Get in touch with our team for quick support
Not the Right Trial for You?
Explore thousands of other clinical trials that might be a better match.
Sign up to get personalized trial recommendations delivered to your inbox.
Already have an account? Log in here
Published Research Related To This Trial
Processed electroencephalography-guided general anaesthesia to reduce postoperative delirium: a systematic review and meta-analysis.
Matthew Sumner, Carolyn Deng, Lis Evered...
https://pubmed.ncbi.nlm.nih.gov/35183345Using the Delphi process to determine the minimum clinically important effect size for the Balanced-2 randomised controlled trial.
Carolyn Deng, David Sidebotham
https://pubmed.ncbi.nlm.nih.gov/37144615Recommendations for the nomenclature of cognitive change associated with anaesthesia and surgery-2018.
L Evered, B Silbert, D S Knopman...
https://pubmed.ncbi.nlm.nih.gov/30336844