RecruitingInterventional

Randomised controlled trial of dialysate cooling for preservation of cognitive function in haemodialysis

This study aims to discover if slightly cooling the fluid used during haemodialysis can help protect thinking and memory skills in people undergoing this treatment. Many people on dialysis experience problems with their memory and ability to focus, as dialysis can affect blood pressure and blood flow to the brain. Currently, there are no specific treatments for these issues. This research will randomly assign participants to either their usual dialysis or dialysis with cooler fluid. After one year, researchers will check if thinking and memory have been maintained. Participants must be over 18 and receiving regular haemodialysis. The study is funded by the National Institute for Health and Care Research (NIHR) and will take place in the UK from April 2026 to October 2027.

At a glance

Status

Recruiting

Sponsor

University Hospitals of Derby and Burton NHS Foundation Trust

Enrolment target

356

Start

01 Apr 2026

Estimated completion

01 Oct 2026

Cognitive function in haemodialysis patients

What is this study about?

Many people who receive haemodialysis (a type of kidney dialysis) often experience problems with their thinking and memory. These difficulties can make everyday tasks harder, like remembering appointments or solving simple problems. Scientists believe this might be because haemodialysis can affect a person's blood pressure and how blood flows to the brain.

Currently, there isn't a specific treatment available to help protect thinking and memory skills in people on dialysis. However, some earlier research has shown that slightly cooling the fluid used in the dialysis machine, called 'dialysate cooling', can have good effects on blood pressure. This study wants to find out if this simple change – lowering the temperature of the dialysis fluid by just half a degree Celsius – could also help protect people's thinking and memory over time.

By carefully studying participants, this research hopes to discover if dialysate cooling could be a way to keep memory and thinking abilities steady for those undergoing long-term haemodialysis. This is an important step towards finding new ways to improve the quality of life for people with kidney disease.

Key takeaways

This study aims to help people on haemodialysis keep their thinking and memory sharp.
It tests if slightly cooling dialysis fluid is beneficial.
Participation involves continuing your usual dialysis, with one group receiving cooler fluid.
You will complete memory and thinking tests at the beginning and end of the study.
The study lasts for one year and is considered safe.
This research hopes to improve the future care for people with kidney disease.

Who may be eligible?

This study is looking for volunteers who are adults aged 18 or older. You must be currently receiving regular haemodialysis treatment in a special clinic or hospital ('in-centre'). You also need to be able to understand the study and willingly agree to take part by signing a form.

However, some people won't be able to join. This includes if you have been diagnosed with dementia, if you are unable to give your consent, or if you have dialysis less than three times a week. Pregnant individuals also cannot take part in this study.

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 18 years old or over?
Are you currently having haemodialysis at a clinic or hospital (not at home)?
Are you able to understand the study information and give your permission to take part?
Do you have regular dialysis at least three times a week?
Are you not pregnant?
Have you not been diagnosed with dementia?

Answer every question to see your result.

What does participation involve?

If you decide to take part in this study, you will continue with your usual haemodialysis treatment. You'll be placed into one of two groups by chance (like flipping a coin): one group will have their dialysis fluid cooled by half a degree Celsius, while the other group will have their usual dialysis temperature. You won't know which group you are in.

At the start of the study and again after one year, you will be asked to complete some questionnaires and special tests designed to check your thinking and memory skills. The study will last for one year in total from the time you join. All your dialysis sessions will take place as normal during this period.

Potential risks and benefits

Participating in this study might help us understand if a small change to dialysis can make a big difference to thinking and memory for people on haemodialysis. This could lead to better care in the future. The method of cooling the dialysis fluid is generally considered safe and is not thought to be riskier than having regular dialysis. Some people might find they feel a bit colder than usual during their dialysis session with cooled fluid. You are free to withdraw from the study at any time without giving a reason, and this will not affect your usual medical care.

Locations (3)

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

University Hospitals of Derby and Burton NHS Foundation Trust
Unverified
Derby, England
Nottingham University Hospitals NHS Trust
Unverified
Nottingham, England
University Hospitals of Leicester NHS Trust
Unverified
Leicester, England

Common questions

What is haemodialysis?

Haemodialysis is a medical treatment that cleans your blood when your kidneys can no longer do this properly.

What does 'cognitive function' mean?

It refers to your brain's abilities like thinking, remembering, paying attention, and solving problems.

Will I know if I'm getting the cooler dialysis fluid?

No, this is a 'blinded' study, meaning neither you nor your care team will know if you are in the cooled fluid group or the standard fluid group.

How long will I be in the study?

If you join the study, you will participate for one year.

Who is paying for this research?

The study is funded by the National Institute for Health and Care Research (NIHR) in the UK.

How to find out more

Derby Clinical Trials Support Unit

uhdb.coolhdstudy@nhs.net +44 (0)1332340131 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.