Exposure to general anaesthesia and surgery in older patients is associated with a subtle decline in cognitive z-scores, suggests a new study in the British Journal of Anaesthesia.
Researchers analysed the longitudinal cognitive function trajectory in a cohort of patients (n=1819) aged 70-89 years at enrolment and its association with exposure to anaesthesia and surgery.
In adjusted linear mixed models, any exposure to anaesthesia and surgery in the previous 20 years was associated with a more negative slope for global cognitive function in comparison to those unexposed. A more prominent decline (0.2 standard deviations more than expected decline as a result of ageing) was also found in previously unexposed participants who had any surgery with anaesthesia after enrolment in the study.
The accelerated cognitive decline was predominantly related to impairments in memory and attention/executive function.
Although, it was not possible to determine causality, this small cognitive decline could be meaningful for individuals with already low baseline cognition, the study concluded.
“This study provides further reasons for clinicians to start performing routine preoperative cognitive evaluations of the elderly to further clarify an individual’s risk of exposure to surgery and anaesthesia,” said senior study author Dr Juraj Sprung, a Mayo Clinic anaesthesiologist.