A recent study published in JAMA Internal Medicine has discovered a link between developing postoperative delirium and a 40% faster rate of cognitive decline. This emphasizes the need for delirium prevention to maintain the brain health of older adults who undergo surgery.

“Delirium is associated with faster cognitive decline,” warns first author Zachary J. Kunicki. “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.”

“This study has the longest follow-up period of any study examining persons with delirium following surgery,” adds senior author Sharon K. Inouye, highlighting, “while future studies are needed, this study raises the possibility that delirium may predispose to permanent cognitive decline and potentially dementia. This highlights the importance of delirium prevention to preserve brain health in older adults who undergo surgery.”

In older adults, delirium is the most frequently occurring post-operative complication and is linked to negative consequences, such as long-term cognitive decline and the onset of dementia.

The article titled “Six-year cognitive trajectory in older adults following major surgery and delirium” was co-authored by Richard N. Jones, ScD from Warren Alpert Medical School of Brown University, while the SAGES Study (NIH Grant No. P01AG031720) funded this extensive observational research and was overseen by Principal Investigator Inouye.

For up to 6 years, the SAGES cohort has been monitoring the cognitive function of 560 elderly individuals aged 70 or above, with assessments conducted every 6 months for the first 36 months, followed by annual evaluations.

They utilized an extensive cognitive testing battery, consisting of 11 distinct assessments, and discovered that cognitive changes after surgery are intricate and impacted by delirium at each stage. Typically, there is a sudden decline in cognitive function one month after surgery, followed by an improvement at two months after surgery, a stable period from 6-30 months after surgery, and then a gradual decline from 3-6 years after surgery.

According to the study, individuals who experienced delirium after surgery showed a more drastic drop in cognitive function at the one-month mark, followed by greater recovery at two months, but a faster decline in cognitive function throughout the six-year period following surgery.

These findings indicate that delirium could either directly contribute to cognitive decline, or serve as an indicator for individuals who are at a higher risk of experiencing more rapid cognitive decline in the future.

Further research may help determine which of these hypotheses, if not both, provides the most plausible explanation for the correlation between delirium and cognitive decline.

Source: 10.1001/jamainternalmed.2023.0144

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