Dialysate Cooling for the Preservation of Cognitive Function in People Receiving Haemodialysis

When a person's kidneys are not working properly, they need a life-saving treatment called haemodialysis three times a week to filter the waste and extra fluids from the blood. 25 000 adults in the United Kingdom are currently having haemodialysis and unfortunately more than two-thirds of these people experience problems with thinking and memory, which may lead to dementia. These problems tend to worsen more rapidly than people who are not on haemodialysis. This decline in brain function can make it harder for people to do everyday tasks, increase their reliance on others, and lower their overall quality of life. It also raises the chances of needing hospital care and can shorten their lifespan.

One reason for this decline in thinking and memory could be the dialysis treatment itself. Research has shown that blood flow to the brain can drop during dialysis. If this happens regularly, it can harm the brain over time. Earlier studies found that cooling the dialysis fluid slightly (to 0.5°C below body temperature) helped people tolerate dialysis better and showed less brain damage on magnetic imaging brain scans (MRI) after a year, compared to those who had haemodialysis without cooling the dialysis fluid. However, the investigators still don't know if this brain protection translates into better thinking and memory for people on haemodialysis.

This study will see if cooling the dialysis fluid helps preserve thinking and memory function.

The investigators will invite participants at three hospitals with haemodialysis centres to take part. Those who agree will be randomly assigned to either standard dialysis or cooled dialysis. The investigators will assess participants' thinking and memory functions using special tests at the start of the study and again after a year. By comparing the results from both groups, the investigators hope to see if the cooled dialysis really helps protect brain.