It has been widely assumed that older adults may experience memory loss and other cognitive problems following surgery. But in a study conducted at Washington University School of Medicine questioning those assumptions, researchers were not able to detect long-term cognitive decline attributable to surgery.
“There’s a perception that people go in for surgery, and they aren’t quite the same afterward,” says first author Michael Avidan, MB, BCh, associate professor of anesthesiology and of surgery, who conducted the study with Alex Evers, MD, head of the Department of Anesthesiology and the Henry E. Mallinckrodt Professor of Anesthesiology. “We wondered how reasonable it was to compare people having surgery to people who were perfectly healthy. We thought a better comparison group might be people who were equally ill.”
Avidan and Evers examined data from Washington University’s Alzheimer’s Disease Research Center (ADRC), which annually tests both healthy volunteers and those with dementia, beginning at age 50. Having years of data made it easier to map a person’s cognitive trajectory before and after surgery or illness.
“We were able to compare groups of patients over time, and we did not detect evidence of long-term cognitive decline attributable to surgery,” Evers says. “If older people physically recover from surgery, they should generally return to their previous level of cognitive ability, too.”
The investigators acknowledge their study, published in the November issue of the journal Anesthesiology, is not the final word. Some patients may be more vulnerable to cognitive decline following surgery and anesthesia, and further research is warranted, they saw. But they add the findings should provide reassurance for most seniors facing surgery.
“If you’re elderly and need surgery, even if you already have early dementia, whether or not you decide to have surgery should depend on surgical risks and benefits, and not the hypothetical possibility of cognitive problems,” says Avidan.
Avidan, MS, et al. Long-term cognitive decline in older subjects was not attributable to noncardiac surgery or major illness. Anesthesiology, vol. 111:5, pp. 1651-1657. Nov. 2009