Severity of Delirium After Surgery Linked to Cognitive Decline

Severity of delirium in post-surgical patients was directly linked to the level of cognitive decline later in life, reveals a new study.

The research team from the Harvard affiliated Hebrew SeniorLife Institute for Aging Research (IFAR) worked in collaboration with scientists from Beth Israel Deaconess Medical Center (BIDMC), Harvard Medical School (HMS), and Brown University.

‘Delirium patients are at greater risk for cognitive decline after surgery and the severity increases depending on the severity of delirium.’

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Findings from this study were published in the Journal of Alzheimer's Disease.

Delirium is a common, serious, often fatal disorder affecting as many as 50 percent 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.

ICU Delirium - Causes, Symptoms, Diagnosis, Treatment
ICU delirium is the most dreaded and least diagnosed complication of an illness which requires treatment in the critical care unit.

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."

Decreased Consciousness - Symptom Evaluation
Consciousness can be decreased to various degrees and result in conditions like delirium, stupor, coma, persistent vegetative state, minimal conscious state and brain death.

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.

Delirium - Types, Causes, Symptoms, Signs, Diagnosis, Treatment
Delirium is a sudden disturbance in mental function that causes confusion and decreased awareness of one’s environment. It is classified into three subtypes – hyperactive, hypoactive and mixed.

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."

Source-Eurekalert