TUESDAY, March 21, 2023 (HealthDay News) -- Older adults often develop delirium after surgery, and new research finds this is associated with a faster rate of mental decline.

The study highlights the importance of preventing delirium to preserve brain health in older adults who undergo surgery, according to the authors.

“Whether delirium causes this faster rate of decline, or is simply a marker of those who are at risk of experiencing faster rates of decline, is still to be determined,” co-author Zachary Kunicki said in a news release from the Marcus Institute for Aging Research, in Boston.

Kunicki is an assistant professor in the Warren Alpert Medical School of Brown University, in Providence, R.I.

The investigators found a 40% faster rate of cognitive (mental) decline in those who developed delirium compared to those who did not.

Delirium is an altered mental state characterized by confusion and disorientation. Often temporary, it is the most common post-operative complication in elderly patients, the authors noted.

For the study, the researchers followed 560 adults, aged 70 and older, measuring their cognition (or mental status) every six months for 36 months, then annually afterwards for up to six years.

Using a combination of 11 cognitive tests, the investigators found mental changes after surgery are complex and that delirium influences every time point.

Having delirium was associated with a sharper drop in mental skills at one month, greater recovery at two months and then faster decline in all time periods from six months to six years.

These results suggest that delirium may contribute to cognitive decline after surgery. It’s also possible that delirium simply identifies those at risk for future more rapid cognitive decline, the researchers suggested.

“While future studies are needed, this study raises the possibility that delirium may predispose to permanent cognitive decline and potentially dementia," said study co-author Dr. Sharon Inouye, director of the Aging Brain Center at the Marcus Institute.

The findings were published March 20 in JAMA Internal Medicine. The study was funded by the U.S. National Institute on Aging.

More information

The American Medical Association has more on post-surgical delirium.

SOURCE: Hebrew SeniorLife, Marcus Institute for Aging Research, news release, March 20, 2023