Does brain function really decline after hip and knee surgery?
A new study due to launch in the South West aims to explore if brain function declines after hip and knee replacement surgery.
The study, called COMPASS, will begin in the summer and aims to recruit 300 patients from across Plymouth and Exeter.
About 3,000 hip and knee replacements are done every year in the South West. Post-operative cognitive dysfunction (POCD) - a delirium-like complication of major surgery in older people - is common, whether patients have a general anaesthetic or spinal anaesthetic for their surgical procedure. However, it is not known what causes the change (such as the operation itself, exposure to anaesthesia agents, emotional stress, medications, combination of factors) or whether there would be a similar decline in brain function without surgery.
The study is a collaboration between trainees in anaesthetics and trainees in primary care and is being led by South West Anaesthesia Research Matrix (SWARM), an anaesthetic trainee-led audit and research collaborative between six NHS organisations in the region, including University Hospitals Plymouth NHS Trust, Royal Devon and Exeter NHS Foundation Trust, Royal Cornwall Hospitals NHS Trust, Torbay and South Devon NHS Foundation Trust, Northern Devon Healthcare NHS Trust and Taunton and Somerset NHS Foundation Trust.
It is also supported by the NIHR Clinical Research Network in the South West, University of Plymouth Faculty of Medicine and Dentistry and the NIHR Collaboration for Leadership in Applied Health Research and Care South West Peninsula (NIHR PenCLAHRC).
Dr Gary Minto, Consultant Anaesthetist and Director of Research at University Hospitals Plymouth NHS Trust and co-founder of SWARM, said: “We know that cognitive function decreases after surgery but what we don’t know is why or whether it would have decreased if surgery had not taken place. We need to understand how and why this cognitive decline develops and find ways to prevent it, since it poses a particularly high risk to the ageing population.
“This study will follow 300 patients over the age of 60 – 150 who are undergoing hip and knee replacement surgery and 150 who are not having surgery but who are of a similar age and demographic to those who are – to see if there is a comparable difference in their cognitive function over a 12 week period.”
Participants in the study will be asked to take an online cognitive function test seven times over the course of three months which will encompass both the pre and post-operative phases.
The opportunity to take part in the study will be offered to patients undergoing surgery for hip and knee replacements at Plymouth’s Derriford Hospital and Torbay Hospital whilst patients not undergoing surgery who wish to take part will be invited from Beacon Medical Group practices in Plymouth and Claremont practice in Exmouth.
“By gaining a more accurate picture of pre-operative cognitive function as well as comparing with an appropriate control group, this will add to the body of evidence regarding those who may be particularly at risk,” said Dr Minto. “By doing this we will be better placed to develop possible preventative interventions as well as advise patients more accurately when discussing the balance of risks and benefits of surgery.”
