Delirium, also known as the acute confusional state, is a decline in mental functioning that develops over a short time, typically hours to days. It is a syndrome that encompasses disturbances in attention, consciousness, and cognition.
The study published in the journal JAMA Neurology conducted a systemic review and analysis of 24 observational studies to determine if delirium was associated with increases of cognitive impairment or dementia. Researchers specifically looked at the first three months after the patient experienced an episode of delirium.
It was found that patients who experienced delirium demonstrated significantly greater cognitive decline than those patients who did not experience any episode.
The study also examined whether delirium uncovers cognitive decline in those who were already compromised with cognitive decline, or whether delirium may potentially cause a decline in mental health. Researchers developed several analyses to test their hypotheses.
This included examining studies that included only non-cognitively impaired individuals at baseline. They also analyzed results that included only cognitively impaired participants and determined the association of the proportion of delirium-present subjects with cognitive outcome. After finding consistent evidence, it was concluded that delirium was causative in decline.
A Variety of Complications
Delirium has been observed in patients with critical illness such as sepsis, respiratory failure, and COVID-19. It has been associated with a variety of complications ranging from increased hospital costs, duration of stay in the hospital, patient stress, and increased mortality and morbidity, including institutionalization.
“From a public health standpoint, it is important that we develop better strategies for addressing outcomes related to delirium, as it is associated with increases in mortality, long-term cognitive decline, and the cost of care,” said Terry Goldberg, Ph.D. a professor of medical psychology (in psychiatry) and anesthesiology at Columbia University Vagelos College of Physicians and Surgeons who led the current study.
“Assuming that delirium occurs in about 20% of those 11.8 million case of individuals older than 65 years who are hospitalized per year, costs attributable to delirium may be between $143 billion and $152 billion owing to longer hospital stays, outpatient visits, nursing home care, and rehabilitation,” said Dr. Goldberg. “And with evidence pointing toward patients with COVID-19 experiencing delirium in ICUs, it is vital that we gain a better understanding of how to help these individuals, as more people than ever are at risk for cognitive decline.”
As research takes form for understanding COVID-19, studies show that it may not only cause intensive breathing problems but may also take aim at the brain. For example, a report published in the journal Brain outlined how delusions plagued nearly a quarter of 43 British COVID patients that were being analyzed as part of a brain study.
As more is learned about COVID-19, it is becoming more apparent that long term research is needed to analyze the effects of delirium caused by COVID-19 and long-term cognitive decline.