Active not recruitingOBSERVATIONAL

Biomarkers Associated With Postoperative Cognitive Dysfunction

This research aims to understand why some older people experience problems with their thinking and memory after major surgery. These problems can range from temporary confusion (delirium) to longer-lasting memory issues, often called postoperative cognitive dysfunction. Currently, it's hard to tell who might be at high risk. The study will look at two main things. First, it will use a harmless brain monitor (like those used for heart tests) during surgery to see if certain brain activity patterns predict confusion afterwards. Second, it will test blood for two proteins that can increase after brain injury. The goal is to find reliable ways to predict who might develop thinking or memory problems up to five years after surgery, helping doctors better support patients.

At a glance

Status

Active not recruiting

Sponsor

University of Oxford

Enrolment target

Start

05 Jan 2023

Estimated completion

01 Jan 2030

Delirium Postoperative Cognitive Dysfunction Cognitive Decline Cognitive Impairment

What is this study about?

This study is looking into a topic called 'postoperative cognitive dysfunction' (POCD). In simple terms, this means problems with thinking, memory, and concentration that can happen after a major operation, especially for people aged 65 and over. These problems can show up in different ways – sometimes as confusion or 'delirium' in the days immediately after surgery, or as more lasting memory and thinking difficulties that emerge months or even years later. We know that these issues can be very upsetting for patients and their families, and they can also impact a person's recovery and overall health after surgery.

Currently, it's quite difficult for doctors to predict who might experience these thinking and memory problems. We don't fully understand all the reasons why they happen, which makes it harder to prevent or treat them effectively. This study aims to change that. Researchers believe that certain clues, called 'biomarkers', could help identify people at higher risk. For example, some theories suggest that very small 'silent strokes' during surgery or how someone's brain reacts to anaesthetic might play a role.

To find these clues, the study will focus on two main areas. Firstly, they will use a special, harmless monitor during surgery called an electroencephalogram (EEG). This device sticks to your head and records the electrical activity of your brain, similar to how an ECG records heart activity. Researchers want to see if specific patterns in brain activity during surgery can predict if someone will become confused in the days after their operation. Secondly, they will take blood samples. They will be looking for two specific proteins in the blood, called neurofilament light chains and tau proteins, which are known to increase after damage to brain cells. The team wants to find out if high levels of these proteins after surgery can predict longer-term memory and thinking problems, even up to five years later. Finding these predictors could eventually help doctors give better care and advice to patients undergoing surgery.

Key takeaways

This study aims to find ways to predict memory and thinking problems after surgery.
It focuses on people aged 65 and over having non-heart surgery.
Tests involve harmless brain monitoring during surgery and blood samples afterwards.
No new medications are given as part of the study.
Participation could last up to five years, with regular follow-up assessments.
The findings could help improve care for future patients.

Who may be eligible?

This study is looking for people who are 65 years old or older. You would need to be having a planned, major surgery, but not on your heart, and your surgery would involve a general anaesthetic (where you're put to sleep completely). It's also expected that you'll stay in hospital for at least two days after your operation, and you must be able and willing to give your informed permission to take part.

There are also some reasons why you might not be able to join. For example, if you already have memory or thinking problems that would make it hard to do special memory tests, or if you are already experiencing confusion before your surgery. You also wouldn't be able to participate if you have a known allergy to the stick-on pads used for the brain monitor, or if you have a history of severe head injury, a known learning disability with a specific brain issue, or a diagnosis of dementia. Finally, if your operation is on the carotid artery (in your neck), you wouldn't be eligible for this particular study.

Basically, the study is for older adults having a common type of major surgery who don't already have significant memory problems or specific medical conditions that might interfere with the study's results.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

Are you 65 years old or older?
Are you having a planned major surgery (not on your heart) under general anaesthetic?
Do you expect to stay in hospital for at least two days after your surgery?
Do you have good memory and thinking abilities, without a diagnosis of dementia?
Are you not allergic to sticky pads used on the skin?
Are you able and willing to give your permission to take part?

Answer every question to see your result.

What does participation involve?

If you decide to take part in this study, here's what would generally be involved:

Before your surgery, study staff would talk to you and ask for your written permission to participate. They would also do some simple assessments to check your current memory and thinking abilities.

During your surgery, a special monitor called an EEG would be gently attached to your scalp. This device is harmless and records your brain's electrical activity while you are under general anaesthetic. You won't feel anything once you're asleep. This is not a treatment, just a measurement.

After your surgery, you would have some repeat memory and thinking assessments. Blood samples would also be taken, sometimes along with routine blood tests, to measure the levels of certain proteins. These assessments and blood tests would happen at a few different times: within five days of your surgery, then at three months, one year, and potentially up to five years after your operation. The total duration of your involvement could therefore be up to five years, though the most frequent checks are in the first year. There is no new medication involved in this study.

Potential risks and benefits

Taking part in this study may not offer direct medical benefits to you personally, but the information collected will be very valuable in helping doctors better understand and potentially prevent thinking and memory problems for future patients after surgery. The risks are generally low; the brain monitoring (EEG) is a routine, harmless procedure, and blood tests carry only minor risks like bruising or discomfort. You also always have the right to withdraw from the study at any time, for any reason, without it affecting your medical care.

Locations (1)

Some site locations are approximate. We're improving this — please verify with the trial team before travelling.

Royal Berkshire NHS Foundation Trust
Verified postcode
Reading, United Kingdom

Common questions

What is postoperative cognitive dysfunction (POCD)?

It's a term for confusion, memory problems, or difficulty thinking clearly that can happen after a major operation, especially in older people.

Is the brain monitoring (EEG) safe?

Yes, EEG is a very safe and harmless test. It simply records your brain's electrical activity and doesn't involve any shocks or discomfort.

Will I get drugs as part of the study?

No, this study does not involve giving you any new medications; it's purely about observations and measurements.

How long will I be involved in the study?

You could be involved for up to five years, with assessments at specific times after your surgery, particularly in the first year.

Can I leave the study if I change my mind?

Yes, you can withdraw from the study at any time without having to give a reason, and it won't affect your medical care.