Severity of Post-Operative Delirium Relates to Severity of Cognitive Decline

28 November 2017

Cognitive decline after surgery is biphasic and accelerated among person with delirium.

Boston—Researchers from the Harvard affiliated Hebrew SeniorLife Institute for Aging Research (IFAR), in collaboration with scientists from Beth Israel Deaconess Medical Center (BIDMC), Harvard Medical School (HMS), and Brown University, have found increasing evidence that the level of delirium in post-surgical patients is associated with the level of later cognitive decline in those same patients. Findings from this study were published today in the Journal of Alzheimer’s Disease.

Delirium is a common, serious, often fatal disorder affecting as many as 50% of older people during the course of surgery or hospitalization and costing more than $164 billion per year. Delirium has been associated with increased functional decline, prolonged hospital stays, higher rates of institutionalization and greater mortality. Delirium is also associated with a significant decline in cognitive ability. The authors of this study have found that for those patients who develop delirium and later cognitive impairment, the severity of cognitive impairment has a direct correlation to the severity of prior delirium.

Sarinnapha Vasunilashorn, Ph.D., Division of General Medicine and Primary Care at BIDMC and contributing author on this study said, “Although the short-term adverse affects of delirium are well-recognized, our results underscore important implications for longer-term prognosis. The findings suggest that for patients with moderate to severe delirium, the decline in cognition may be both substantial and long-term, and most notably, it exceeds the rate of decline observed in patients with dementia.”

Researchers studied a group of 566 patients over a total of 3 years. Before their surgeries, none of these patients displayed signs of dementia. After surgery, a total of 134 participants displayed signs of delirium, based on their evaluations using the Confusion Assessment Method (CAM). Of these 134 participants, those who displayed the highest severity of delirium later developed the most severe cognitive decline.

Sharon K Inouye, M.D., M.P.H, Director of the Aging Brain Center at Hebrew SeniorLife’s Institute for Aging Research and senior author on the study said, “These results challenge the idea that delirium is reversible with only acute complications. Though delirium generally subsides after a period of time, it appears to have lasting effects, the severity of which are related to the severity of the delirium itself. This work suggests the need to target patients with high delirium severity for strategies to prevent progressive cognitive decline as they are at increased risk for dementia.”

Vasunilashorn SM, Fong TG, Albuquerque A, Marcantonio ER, Schmitt EM, Tommet D, Gou Y, Travison TG, Jones RN, Inouye SK (2018) Delirium Severity Post-Surgery and its Relationship with Long-Term Cognitive Decline in a Cohort of Patients without Dementia. J Alzheimers Dis, doi: 10.3233/JAD-170288.

Media Contact:
Courtney Howe
617-363-8267
courtneyhowe@hsl.harvard.edu

About Institute for Aging Research
Scientists at the Institute for Aging Research seek to transform the human experience of aging by conducting research that will ensure a life of health, dignity and productivity into advanced age. The Institute carries out rigorous studies that discover the mechanisms of age-related disease and disability; lead to the prevention, treatment and cure of disease; advance the standard of care for older people; and inform public decision-making. The Musculoskeletal Center within IFAR studies conditions affecting bone, muscle, and joint health with aging.

About Hebrew SeniorLife
Hebrew SeniorLife, an affiliate of Harvard Medical School, is a national senior services leader uniquely dedicated to rethinking, researching and redefining the possibilities of aging. Based in Boston, the non-profit, non-sectarian organization has provided communities and health care for seniors, research into aging, and education for geriatric care providers since 1903. For more information about Hebrew SeniorLife, visit http://www.hebrewseniorlife.org, follow us on Twitter @H_SeniorLife, like us on Facebook or read our blog.

ABOUT THE JOURNAL OF ALZHEIMER’S DISEASE (JAD)
The Journal of Alzheimer's Disease (http://www.j-alz.com) is an international multidisciplinary journal to facilitate progress in understanding the etiology, pathogenesis, epidemiology, genetics, behavior, treatment and psychology of Alzheimer's disease. The journal publishes research reports, reviews, short communications, book reviews, and letters-to-the-editor. Groundbreaking research that has appeared in the journal includes novel therapeutic targets, mechanisms of disease and clinical trial outcomes. The Journal of Alzheimer's Disease has an Impact Factor of 3.731 according to Thomson Reuters' 2017 Journal Citation Reports. The Journal is published by IOS Press (www.iospress.com).