Aging

Blood Test Can Alert Doctors to Delirium Risk

artsy photo depicting two nurses walking down hospital corridor in the view point of someone experiencing the effects of confusion or delirium


Researchers at UConn Health and Beth Israel Deaconess Medical Center have found that a blood test could make it easier to identify patients at risk for delirium, the sudden, acute state of confusion that most often affects older adults and incurs $6.9 billion in medical costs each year in the U.S. Their study, published online in The Journal of Gerontology: Medical Sciences, reports that elevated blood levels of specific proteins called cytokines can hint that a patient will develop delirium during a hospital stay.

If you do things such as improve a patient’s vision and hearing, reorient them to where they are regularly, promote restful sleep, increase mobility, and stop medications that could be making the delirium worse, all that can help.

Dr. George Kuchel, director of the UConn Center on Aging and one of the authors of the study, says the suspected blood signature for delirium shows two cytokines at higher-than-normal levels in patients who develop delirium. Both cytokines are associated with inflammation.

Researchers don’t yet know exactly how inflammation and delirium are linked. The two cytokines the researchers saw in the blood signature, interleukin-6 and interleukin-2, can cause swelling of the membrane around the brain. Chronic stress from low-level illness can also elevate both cytokines and stress hormones such as cortisol, which over the long term can shrink part of the brain and perhaps increase an elderly person’s susceptibility to delirium.

Kuchel and his colleagues worked with patients who participated in the Successful Aging after Elective Surgery (SAGES) study to get a better handle on the relationship between inflammation and delirium. This large study, sponsored by the National Institute on Aging, has been following 566 surgical patients over the age of 70 for the past five years, with the goal of finding new approaches to prevent delirium and its long-term consequences in older adults.

The UConn study found that patients who developed delirium had higher levels of interleukin-2 than non-delirium patients at all times they were tested: before surgery, in the first two days afterward, and one month later.

This is the first study to look at cytokine levels in older surgical patients at several points in time, both before and after surgery. The results need to be replicated in other studies, but if they prove to be generally true, the blood signature could provide a quick way to alert doctors and nurses to seniors at higher risk of delirium. They can then take extra precautions to keep the patients oriented.

“If you do things such as improve a patient’s vision and hearing, reorient them to where they are regularly, promote restful sleep, increase mobility, and stop medications that could be making the delirium worse, all that can help,” says Kuchel.