Cognitive Assessment And Post-Operative Complications After Surgery: Linking Anaesthesia And Risk

Many older people can experience confusion, memory problems, or a decline in their thinking after major surgery. These problems are sometimes called 'postoperative neurocognitive disorders' or PND and can affect recovery and a person's ability to live independently. The investigators want to find out the best way to study these problems in older patients undergoing surgery. This is a 'feasibility study', which means we are testing the research methods. The investigators want to see if it is possible to ask participants to do memory tests and give blood samples before and after their operation. The investigators are hoping to include around 40 patients over 2 years in this study. The investigators will compare performance in memory (cognitive assessment) findings before and after surgery and link this to data taken from the anaesthetic, including the types of drugs used, duration, brain features from processed electroencephalogram monitoring and standard recommended monitoring. In addition the investigators will link this to blood sample markers of brain health and function (biomarkers). The results of this study will help the investigators plan a much larger study in the future, with the ultimate goal of making surgery safer for the brain.

Inclusion Criteria: * Age ≥ 70 * Seen in the Perioperative medicine for Older People undergoing Surgery (POPS) clinic * Scheduled for colorectal or urological surgery with expected anaesthesia time over 60 minutes Exclusion Criteria: * Regional anaesthesia only * Planned day surgery or expected hospital stay \< 24 hours * Expected to remain sedated and ventilated for \> 24 hours postoperatively * Participant does not wish to remain in the study if capacity is lost during the study CO-ENROLMENT * As this is a non-intervention study, co-enrolment will be permitted in other studies that do not conflict with this protocol.