The impact of the peri‐operative period on cognition in older individuals

This review aims to highlight the importance of peri‐operative and longer‐term postoperative cognitive changes and to put them in the context of other cognitive disorders. Cognitive decline is common among the elderly and is impacted by many factors, both known and unknown. Individuals aged 65 years and above comprise the most frequent users of the healthcare system; thus this group is at risk of both cognitive decline associated with ageing, such as mild cognitive impairment and Alzheimer's disease, and cognitive disorders associated with surgery and anaesthesia, including delirium and postoperative cognitive dysfunction. Until now research and management of geriatric cognitive disorders has occurred in isolation from peri‐operative medicine and research, such that any overlap between the cognitive disorders has been largely overlooked. Factors contributing to this division include the classification of geriatric cognitive disorders according to Diagnostic and Statistical Manual of Mental Disorders ( DSM ) and International Classification of Diseases ( ICD ) criteria, while cognitive disorders associated with the peri‐operative period are largely research diagnoses. Given the large overlap between individuals at risk of cognitive decline (those aged 65 or above) and individuals exposed to surgery and anaesthesia, consideration of the role of the peri‐operative period in geriatric cognitive disorders is imperative. Recent work investigating postoperative cognitive dysfunction has identified baseline cognitive function as a more significant predictor of further decline than increasing age, suggesting that preoperative cognitive trajectory may be the most important factor in determining postoperative decline. Both animal and human data provide evidence of a role of inflammation in cognitive decline, although this area requires further research to definitively identify associations and possible therapeutic strategies. Given the ageing population and the associated healthcare costs of caring for an increasing number of individuals suffering cognitive decline, any insults that exacerbate this problem need to be avoided. Understanding the overlap between geriatric and postoperative cognitive disorders is essential to ensure appropriate healthcare management of the elderly.