People who have episodes of delirium at risk of developing long-term decline in brain abilities, says study
An episode of delirium might unleash long-lasting effects on mental capabilities, robbing people of their ability to think, remember and judge situations, according to a new study. Now, with the condition becoming more prevalent in the Covid-19 era, experts are calling for more research on the topic.
Delirium affects the brain, resulting in mental confusion and hallucinations. It mainly affects people over the age of 65, especially those who are battling life-threatening diseases such as sepsis or respiratory failure. It is also seen in patients needing intensive care or after surgery. Now, more younger adults are also experiencing it, thanks to Covid-19.
"Delirium is associated with a variety of complications, ranging from patient and family stress, increased hospital costs, increased duration of hospital stay, escalation of care, and increased mortality and morbidity including institutionalization," says Dr Terry Goldberg, professor of medical psychology and anesthesiology at Columbia University Vagelos College of Physicians and Surgeons, and one of the lead authors of the study.
To investigate whether a brush with delirium could independently trigger long-term cognitive decline, Goldberg and his team mined data from previous studies — 23 of them. From these studies, they identified 3,562 patients with delirium and 6,987 without it. They compared the two groups to understand the prevalence of cognitive impairment or dementia.
Their analysis found a significant association between the two conditions three months later. What is more, the risk of developing long-term impairment or dementia was double for people with delirium, they add.
Delirium — induced by surgery and intensive care — could both lead to lasting impacts on cognition. Researchers suspect that the immune system's response could be involved.
After finding a link, the team looked for more definitive evidence to show that delirium indeed caused a cognitive decline. Previous studies suggested that delirium worsened conditions for people with already compromised mental abilities. After analyzing the data, the authors found contradictory evidence, suggesting that it could be initiating the mental impairments.
Delirium could take a toll on the people it affects, both in terms of health and economic costs. "Assuming that delirium occurs in about 20% of those 11.8 million cases of individuals older than 65 years who are hospitalized each 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," Dr Goldberg explains.
Some measures such as orientation, regular sleep-wake cycle, access to glasses and hearing aids, anti-inflammatory drugs, cognitive-enhancing drugs, as well as cognitive training, could help, say researchers. But they call for more research as the new coronavirus is affecting the brain. A previous study detected delirium in patients who sometimes do not sow typical respiratory symptoms.
"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," Dr Goldberg adds. The study was published in JAMA Neurology.