Exposure to anaesthetic agents, cognitive functioning and depressive symptomatology in the elderly

Abstract

Background: Anaesthesia could provoke persistent alterations in specific cognitive domains in the elderly where ageing-related neuronal changes may exacerbate pharmacotoxic effects. Aims: To evaluate anaesthesia effects on the incidence of cognitive dysfunction after orthopaedic surgery in elderly patients. Method: A total of 140 patients over the age of 64 years completed a full range of computerised cognitive tests. The study takes into account effects of pre-operative cognitive dysfunction, depressive symptomatology and ability to perform activities of daily living. Results: Postoperative cognitive decline persisted for up to 3 months in 56% of subjects. Dysfunction was limited to verbal, visuo-spatial and semantic abilities and secondary and implicit memory. Age, Iow educational level, pre-operative cognitive impairment or depression are risk factors. Conclusions: Cognitive functions are not equally affected, type of impairment being determined by the risk factors described above and anaesthesia type.