Anesthesia Not Linked to Cognitive Impairment in Older Adults
Research done in 2016 suggests older patients should not feel reluctant to have life enhancing surgeries due to concerns that undergoing anesthesia may boost their risk of developing cognitive issues. In a study of more than 8,500 middle-aged and elderly Danish twins published in Anesthesiology, the official medical journal of the American Society of Anesthesiologists (ASA), researchers found no clinically significant association between major surgery and general anesthesia with long-term cognitive decline.
A release from the society quotes study lead author Unni Dokkedal, M.P.H., Unit of Epidemiology, Biostatistics, and Biodemography, University of Southern Denmark, as saying, “Our use of twins in the study provides a powerful approach to detect subtle effects of surgery and anesthesia on cognitive functioning by minimizing the risk that the true effects of surgery and anesthesia are mixed up with other environmental and genetic factors. We found no significant cognitive effects related to surgery and anesthesia in these patients, suggesting that other factors, such as preoperative cognitive levels and underlying diseases, are more important to cognitive functioning in aging patients following surgery.”
More than one in 10 people who have surgery are 65 or older and advanced age can affect the potential for surgical risks. Postoperative cognitive dysfunction for a few weeks after surgery is one of these potential risks, but the effects of surgery, anesthesia, pre-existing health conditions, and other factors have been unclear. Whether this short-term postoperative cognitive dysfunction leads to long-term memory loss and lessened ability to learn, concentrate and think is uncertain, but the current study suggests it is unlikely.
In the study, researchers examined the association between exposure to surgery and level of cognitive functioning in a sample of 4,299 middle-aged twins younger than 70 and 4,204 elderly twins who were aged 70 or older. Results from cognitive tests of twins who had either major, minor, hip and knee replacement or other surgery within 18 to 24 years before cognitive examination were compared to the cognitive results of a reference group, comprised of twins who had no surgical procedures. Test results were also compared in an intrapair analysis of twins, one of whom was exposed to surgery while the other was not, to assess genetic and shared environmental confounding.