Exposure to surgery with general anesthesia is tied to a subtle decline in memory and thinking skills in older adults, according to a new Mayo clinic study published in the British Journal of Anaesthesia.
Although the decline in brain function was small, the finding may have significant implications for older patients with already low cognitive function or pre-existing mild cognitive impairment, the researchers note. For example, in older adults with borderline cognitive issues that are not yet clinically obvious, exposure to anesthesia and surgery may unmask underlying problems with memory and thinking.
“We need to be sure that patients considering surgery, and their families, are properly informed that the risk of cognitive dysfunction is possible,” says Juraj Sprung, M.D., Ph.D., a Mayo Clinic anesthesiologist, who is the study’s senior author.
“In addition, alternative strategies should be discussed with patients before surgery is undertaken for those deemed to be at high risk. 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 anesthesia. This initiative has been endorsed by the American Geriatrics Society but was not widely put into clinical practice.”
The link between surgery with anesthesia and cognitive decline in older adults has been debated among experts for many years. Animal studies have suggested that exposure to inhaled anesthetics may be related to brain changes linked to Alzheimer’s disease; however, most previous studies in humans have not consistently found a link between anesthesia and impaired brain function.
In this study, the researchers analyzed 1,819 participants (ages 70 to 89 at time of enrollment) from the Mayo Clinic Study of Aging, a long-term epidemiologic and population-based study looking at age-related cognitive changes. Participants underwent cognitive evaluations at roughly 15-month intervals.
The researchers looked at whether exposure to surgery and anesthesia during the 20-year period prior to enrollment was associated with a decline in cognitive function and whether exposure to anesthesia after study enrollment as an older adult was associated with impaired cognition.
Although many older adults experience cognitive decline as part of the normal aging process, the study found that cognitive decline following exposure to anesthesia and surgery was slightly accelerated beyond what is associated with normative aging.
The researchers emphasize that it is not possible to know whether anesthesia, surgery or the underlying conditions necessitating surgery caused the decline, however.
Source: Mayo Clinic