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Sedative-associated delirium increases risk of dementia

Mar. 29, 2018, 10:29 AM

 

A Vanderbilt study of more than 1,000 intensive care unit patients around the country, nearly three-fourths of whom experienced delirium, showed that many drugs given to sedate patients in the ICU are actually increasing their chances of — and duration of — delirium instead of helping them recover.

The study appeared in the March issue of The Lancet Respiratory Medicine.

Delirium is a sudden disruption of consciousness and cognition marked predominantly by inattention and sometimes by vivid hallucinations and delusions.

Affecting about 7 million hospitalized patients each year, and sometimes persisting for months after discharge from the hospital, the disorder can cause sudden and severe decline in mental function or is a strong predictor of development of acquired dementia that clinically is of the severity of Alzheimer’s disease.

While delirium and dementia can coexist, they are completely different illnesses — dementia develops gradually and worsens progressively, while delirium occurs suddenly and typically fluctuates during the course of a day.

Wes Ely, MD, MPH

The Vanderbilt study, led by senior author, Wes Ely, MD, MPH, and first author Tim Girard, MD, MSCI (now at the University of Pittsburgh), showed that 71 percent of the participants experienced delirium at some point during the study, 69 percent had multiple causes of delirium, more than half had drug-induced delirium, and only one-third had a single cause.

There are multiple causes of delirium including sepsis, hypoxemia (low oxygen), metabolic problems such as liver and kidney disease and drugs given in the ICU.

“When you’re in the ICU and the team is trying to treat you, we’re also thinking about how to keep you safe and comfortable during that time,” said Ely, Grant W. Liddle Professor in the Vanderbilt University School of Medicine. “You come in with a problem and we start taking care of that. In the meantime we used to keep you sedated and immobilized, and we used to think that having the family around was not important.

“The culture of the ICU has traditionally been dictated by some de facto norms over the past 20-30 years,” he said. “We are correcting that now. Before our research began to change things, we had allowed ourselves to keep a patient deeply sedated, immobilized and without a lot of engagement with their loved ones. What we did was organize a system of care that didn’t look at the whole person all too often.”

Ely said that Vanderbilt is helping lead the charge to recreate ICU environments that welcome the family and look at patient as a whole person during treatment, but there is still work to be done to spread what is called “ICU Liberation.”

“We’ve been working on this hypothesis for almost two decades,” Ely said. “We’re giving patients sedatives to help them. We’re not saying to never use sedation drugs. We’re saying ‘let’s modify our patient management, the way we use the drugs, use them to get the patient comfortable while initiating life support, then as soon as they’re on the ventilator, let’s cut them way back and let the patient wake up.’

“Let’s give them back their eyeglasses, their hearing aids, fix their disrupted sleep and get them out of bed.”

The Vanderbilt Delirium and Cognitive Impairment Research group’s research has focused on improving the care and outcomes of critically ill patients with ICU-acquired brain disease (manifested acutely as delirium and chronically as long-term cognitive impairment).

Through their ICU Delirium website (www.icudelirium.org), which Ely founded, he and his colleagues at Vanderbilt and the VA have identified acute brain dysfunction (delirium) as one of the most critical problems facing ICU patients.

Their studies have linked delirium with an increased risk of long-term cognitive impairment (acquired dementia) and mortality, prolonged ICU and hospital lengths of stay and significantly higher medical costs.

They have developed and validated a clinical measurement tool, the Confusion Assessment Method for the ICU (CAM-ICU), which has been translated into more than 30 languages and is recommended as standard of care by the Society for Critical Care Medicine (SCCM) for all patients on mechanical ventilation.

Ely and his colleagues also helped develop the newly revised “ABCDEF bundle” of protocols and guidelines, which interprofessional care teams can implement in partnership with patients and families to ensure a safe and comfortable ICU environment.

“We’re saying use the ABCDEF bundle like an airline pilot uses the checklist on an airplane, to make sure everything is safe. It (the bundle) works, saves lives, gets people out of the ICU sooner, prevents bounce backs to the ICU and people are discharged less often to nursing homes,” Ely said of data currently under review.

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