Perioperative cognitive disorders (POCD) is an umbrella term used to describe post-operative delirium, and longer term neurocognitive dysfunction after surgery. Delirium is an acute impairment of brain function associated with surgery and systemic illness. Delirium affects up to 50% of older people admitted to general hospitals for elective surgery, and is associated with increased postoperative mortality and patient distress. Longer term changes to a person’s brain function can also be observed up to 1 year after surgery and critical illness. How people develop delirium and postoperative neurocognitive dysfunction is poorly understood, but may be related to cerebral vascular inflammation and disruption of the blood-brain barrier.
We think that changes in cerebral blood flow may be responsible for the development of peri-operative cognitive disorders, and think that indirect measures of cerebral blood flow may be key both to predict, recognise and monitor POCD. By looking at patients with and without impairments in brain function before, during and after major surgery and critical illness, we aim to improve patient assessment during this time as well as our understanding of the mechanisms underlying POCD and the extent to which changes in cerebral blood flow during major surgery and critical illness affect long term brain function.