Biomarkers Associated With Postoperative Cognitive Dysfunction

University of Oxford

Status

Active, not recruiting

Conditions

Delirium

Cognitive Impairment

Cognitive Decline

Postoperative Cognitive Dysfunction

Treatments

Procedure: Tau protein measurement

Procedure: Neurofilament light chain measurement

Procedure: Intraoperative electroencephalography recording

Study type

Observational

Funder types

Other

Identifiers

NCT05464355

302168 (Other Identifier)

Protocol version 13/06/2022 (Other Identifier)

PID16101

Details and patient eligibility

About

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.

Enrollment

45 estimated patients

Sex

All

Ages

65+ years old

Volunteers

No Healthy Volunteers

Inclusion criteria

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

Exclusion criteria

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