DeliriumNCT05464355
Biomarkers Associated With Postoperative Cognitive Dysfunction
An observational study of Delirium and Postoperative Cognitive Dysfunction, run by University of Oxford at 1 site in United Kingdom.
Trial summary
Loss of cognitive function after major surgery is a significant risk in older people. It can occur acutely in the days after surgery as delirium or in months to years later as a persistent reduction in brain function termed neurocognitive decline. Read more about this study
- Who is it for?
- Ages 65 years and older
- Conditions the study is for
- Delirium, Postoperative Cognitive Dysfunction, Cognitive Decline
- What is being tested?
- Intraoperative electroencephalography recording, Neurofilament light chain measurement and Tau protein measurement
- Type of treatment
- Surgery or procedure
- How many people
- 45 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 5 Jan 2023to Jan 2030
- Phase
- Observational
- 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 65 years and older
- All sexes
- No healthy volunteers
- Older adult
Study population: Adults over 65 years of age having major elective surgery under general anaesthesia
Who may be able to join
- Greater than or equal to 65 years of age
- Having elective non-cardiac surgery under general anaesthesia
- Anticipated to have at least 48 hours of inpatient admission
- Able \& willing to give informed consent
Who cannot join
- Unable to participate in neurocognitive assessments
- Presence of delirium prior to surgery
- Contraindication to use of EEG electrodes (e.g. known allergy to a component of the electrodes)
- Known history of severe traumatic brain injury
- Learning disability specifically with a known structural brain lesion
- Known history of dementia
- Participants undergoing operations on the carotid artery
Trial locations and contacts
1 site in 1 country.
United Kingdom1 site
Royal Berkshire NHS Foundation Trust
Reading, Berkshire, RG1 5AN
About this study
Official title: Feasibility Study of the Use of Biomarkers to Detect Perioperative Brain Injury: the Association Between Serum Neurofilament Light Chains, Tau Proteins, Continuous Intra-operative Electroencephalography, and the Development of Post Operative Cognitive Dysfunction After Surgery
Loss of cognitive function after major surgery is a significant risk in older people. It can occur acutely in the days after surgery as delirium or in months to years later as a persistent reduction in brain function termed neurocognitive decline. Together these conditions are called post operative cognitive dysfunction (POCD). They can be acutely distressing for patients and are associated with other problems after surgery.
The causes of post operative cognitive dysfunction are poorly understood. Studies have been limited by a lack of biomarkers to predict which patients are at high risk of developing POCD. Research suggests silent strokes occurring during surgery and different sensitivities to anaesthetic medicines are associated with POCD.
The project consists of a feasibility study to investigate markers that might predict people over 65 years old getting POCD. The first biomarker is a non-invasive monitor of anaesthetics effects on brain function called electroencephalography (EEG): The investigators will identify which EEG patterns predict delirium within five days surgery. The second set of biomarkers are two blood tests of proteins that increase after strokes: these are neurofilament light chains and tau proteins. The investigators will establish if these can be used to predict having POCD up to one year after surgery and long term cognitive impairment up to 5 years after surgery.
- Being tested
- Intraoperative electroencephalography recording, Neurofilament light chain measurement, Tau protein measurement
- Keywords
- Electroencephalography, Delirium, Neurofilament light chain, Tau protein
- Medical subject headings
- Delirium, Postoperative Cognitive Complications, Cognitive Dysfunction, Charcot-Marie-Tooth disease, Type 1F, Frontotemporal Dementia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Intraoperative electroencephalography recordingProcedure or surgery
Also called EEG recording
Intraoperative electroencephalography measurements, a non-invasive routine monitoring device used during anaesthesia to measure the brain's electrical activity
Neurofilament light chain measurementProcedure or surgery
Also called NfL
Measurement of the level of neurofilament light chain in a blood sample
Tau protein measurementProcedure or surgery
Measurement of the level of tau protein in a blood sample
| Study group | Role | What they receive |
|---|---|---|
| Biomarker monitoring | Not described Receives: Procedure: Intraoperative electroencephalography recording; Procedure: Neurofilament light chain measurement; Procedure: Tau protein measurement |
What is being measured
The primary outcome is the main question the study is designed to answer.
Feasibility to conduct the study
The total number of participants who are successfully recruited, receive the study procedures and complete both 90 day and 1 year follow up after surgery.
Measured: 1 year after surgery
Secondary outcomes (5)
Postoperative delirium incidence and severity
Postoperative delirium identified as being present according to a positive result using 3-Minute Diagnostic Interview for Confusion Assessment Method (3D-CAM) and severity according to the absolute value on the 3D-CAM-Severity which is a scale converting the 3-Minute Diagnostic Interview for Confusion Assessment Method into a scale from 0-7. Higher scores are associated with worse outcome.
Measured: Up to 5 days after surgery
Days alive and at home up to 90 days after surgery
The number of days a participant is alive and how many are spent at home after surgery
Measured: 90 days after surgery
Change in neurofilament light chains and tau proteins levels pre- to post operatively
Measurements of the level of the biomarkers neurofilament light chain and tau protein in plasma
Measured: Up to 2 days after surgery
Postoperative neurocognitive dysfunction and severity
Cognitive impairment measured on Montreal Objective Cognitive Assessment administered by telephone. The scale is 0-22 with higher scores representing better outcome.
Measured: Up to 1 year after surgery
Long term cognitive impairment
Incidence of new diagnosis in primary or secondary care of dementia or mild cognitive impairment
Measured: Up to 5 years after surgery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Jul 2022
- Study start5 Jan 2023
- Primary completionJan 2026 (estimated)
- Study completionJan 2030 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for DeliriumStudies of the same condition, open and under way.
- More trials run by University of OxfordThe sponsor's other registered studies.
- 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
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 45 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Oxford
- Sponsor type
- University, hospital or other
- Collaborators
- Oxford University Hospitals NHS Trust
- Responsible party
- Sponsor
- Investigators
- Martyn Ezra, Principal investigator, University of Oxford
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05464355
- Sponsor's protocol ID
- PID16101
- Other IDs
- 302168, Protocol version 13/06/2022
- Status last verified
- Jun 2025
- First submitted
- 11 Jul 2022
- Last updated
- 22 Jun 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided: Participants will be asked for consent to share anonymized data with other researchers.
Study at a glance
From the registry record, last updated by the sponsor on 22 Jun 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Feasibility Study of the Use of Biomarkers to Detect Perioperative Brain Injury: the Association Between Serum Neurofilament Light Chains, Tau Proteins, Continuous Intra-operative Electroencephalography, and the Development of Post Operative Cognitive Dysfunction After Surgery
- ClinicalTrials.gov ID
- NCT05464355
- Acronym / sponsor ID
- PID16101
- Keywords
- Electroencephalography, Delirium, Neurofilament light chain, Tau protein
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 45 participants (estimated)
- Lead sponsor
- University of OxfordUniversity, hospital or other
- Collaborators
- Oxford University Hospitals NHS Trust
- Study start
- 5 Jan 2023 (actual)
- Primary completion
- Jan 2026 (estimated)
- Study completion
- Jan 2030 (estimated)
- First posted
- 19 Jul 2022 (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.
Loss of cognitive function after major surgery is a significant risk in older people. It can occur acutely in the days after surgery as delirium or in months to years later as a persistent reduction in brain function termed neurocognitive decline. Together these conditions are called post operative cognitive dysfunction (POCD). They can be acutely distressing for patients and are associated with other problems after surgery.
The causes of post operative cognitive dysfunction are poorly understood. Studies have been limited by a lack of biomarkers to predict which patients are at high risk of developing POCD. Research suggests silent strokes occurring during surgery and different sensitivities to anaesthetic medicines are associated with POCD.
The project consists of a feasibility study to investigate markers that might predict people over 65 years old getting POCD. The first biomarker is a non-invasive monitor of anaesthetics effects on brain function called electroencephalography (EEG): The investigators will identify which EEG patterns predict delirium within five days surgery. The second set of biomarkers are two blood tests of proteins that increase after strokes: these are neurofilament light chains and tau proteins. The investigators will establish if these can be used to predict having POCD up to one year after surgery and long term cognitive impairment up to 5 years after surgery.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Biomarker monitoring | – | Procedure: Intraoperative electroencephalography recording, Procedure: Neurofilament light chain measurement, Procedure: Tau protein measurement |
Who may qualify
- Ages
- 65 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Older adult
- Study population
- Adults over 65 years of age having major elective surgery under general anaesthesia
Key inclusion criteria (4 listed)
- Greater than or equal to 65 years of age
- Having elective non-cardiac surgery under general anaesthesia
- Anticipated to have at least 48 hours of inpatient admission
- Able \& willing to give informed consent
Key exclusion criteria (7 listed)
- Unable to participate in neurocognitive assessments
- Presence of delirium prior to surgery
- Contraindication to use of EEG electrodes (e.g. known allergy to a component of the electrodes)
- Known history of severe traumatic brain injury
- Learning disability specifically with a known structural brain lesion
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 |
|---|---|---|
| Intraoperative electroencephalography recordingAlso: EEG recordingIntraoperative electroencephalography measurements, a non-invasive routine monitoring device used during anaesthesia to measure the brain's electrical activity | Procedure or surgery | Biomarker monitoring |
| Neurofilament light chain measurementAlso: NfLMeasurement of the level of neurofilament light chain in a blood sample | Procedure or surgery | Biomarker monitoring |
| Tau protein measurementMeasurement of the level of tau protein in a blood sample | Procedure or surgery | Biomarker monitoring |
Primary outcome
Feasibility to conduct the study
Time frame: 1 year after surgery
The total number of participants who are successfully recruited, receive the study procedures and complete both 90 day and 1 year follow up after surgery.
5 secondary outcomes
Postoperative delirium incidence and severity
Time frame: Up to 5 days after surgery
Days alive and at home up to 90 days after surgery
Time frame: 90 days after surgery
Change in neurofilament light chains and tau proteins levels pre- to post operatively
Time frame: Up to 2 days after surgery
Postoperative neurocognitive dysfunction and severity
Time frame: Up to 1 year after surgery
Long term cognitive impairment
Time frame: Up to 5 years after surgery
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 22 Jun 2025.
- Individual participant dataSharing planned: Undecided. Participants will be asked for consent to share anonymized data with other researchers.
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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. This study is not recruiting at the moment.
Martyn Ezra principal investigator
University of Oxford
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Delirium and Postoperative Cognitive Dysfunction, run by University of Oxford at 1 site in United Kingdom.
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 7 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: under way, not looking for participants, as of the sponsor's last update on 22 Jun 2025. 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 United Kingdom. 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.
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?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Feasibility to conduct the study (time frame: 1 year after surgery). 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 22 Jun 2025.