Hospital study finds connection between dementia, delirium and declining health
More than half of all patients with pre-existing dementia will experience delirium while hospitalized. Failing to detect and treat their delirium early leads to a faster decline of both their physical and mental health, according to health researchers.
“This study is important, as delirium is often overlooked and minimized in the hospital setting, especially in persons with dementia,” said Donna M. Fick, Distinguished Professor of Nursing at Penn State and principal investigator for this study. “And it illustrates that delirium is deadly, costly and impacts patient functioning.”
The researchers followed 139 hospitalized adults, ages 65 and older, with dementia and found that the patients who developed delirium had a 25 percent chance of dying within 30 days, as reported in the current issue of the Journal of Hospital Medicine.
Dementia is an irreversible, progressive condition that affects cognitive and physical function. Symptoms usually occur over months to years and can include memory loss, inability to solve simple problems, difficulties with language and thinking, personality and behavior changes and other mental problems.
Delirium, on the other hand, is a reversible cognitive condition that comes on quickly and if caught and treated early can be resolved. Many of the symptoms of delirium may appear similar to dementia, but signs such as marked inattention and sleepiness or hyperactivity can help differentiate delirium from dementia.
Fick and colleagues focused on this combination of disorders, known as delirium superimposed on dementia (DSD), in this study. The researchers found a 32 percent incidence of new delirium in the hospitalized patients with dementia. These patients stayed in the hospital about four days longer than patients without delirium, and also had a reduced level of physical and mental ability when they left the hospital and at follow-up visits one month later. Additionally, patients with DSD were more likely to have died a month after their hospital stay.
Patients with Alzheimer’s disease who suffered episodes of delirium while hospitalized had a sharply increased rate of mental decline for up to five years after being hospitalized compared to those who did not have any such episodes, according to a study by researchers at The Institute for Aging Research at Hebrew SeniorLife, an affiliate of Harvard Medical School.
The paper, published today in the Archives of Internal Medicine, noted that delirium - an acute decline in cognitive status, particularly attention and executive function, that typically lasts for a day or several days - is highly prevalent among Alzheimer’s patients who are hospitalized.
“Delirium developed in more than half of the patients we studied,” said Alden L. Gross, PhD, MHS, a postdoctoral researcher at the Institute and lead author of the study, the first to examine the significance of the prevalence of delirium over such an extended period of time.
The study showed that patients who had developed delirium during their hospital stays experienced greater cognitive deterioration in the year following the hospitalization than those who had no episodes of delirium and found that mental deterioration proceeded at twice the rate of those who had not suffered such episodes in the year after the hospitalization. Those who suffered episodes of delirium maintained a more rapid rate of cognitive deterioration through up to five years of follow-up.
The researchers studied data collected by the Massachusetts Alzheimer’s Disease Research Center on 263 patients. Data on their cognitive status before and after their hospitalizations was evaluated. There was no difference in the rate of cognitive deterioration between the two groups of patients prior to their hospitalizations. The patients were hospitalized for a variety of reasons, including falls, heart issues and other problems.
Previous studies have found the cost of delirious episodes rivals those for diabetes and heart disease. Decreasing the length of stay by just one day would save more than $20 million in health care costs per year.
Common causes of delirium are infections, dehydration and medication changes. A third of the patients in this study arrived at the hospital dehydrated.
“Preventing delirium is important because we want to discharge patients at their baseline or improved functioning,” said Fick. “We do not want them to go home with worse functioning than when they came into the hospital.”
Delirium is a common neurobehavioral syndrome that occurs across health care settings which is associated with adverse outcomes, including death. There are limited data on long-term cognitive outcomes following delirium. This report reviews the literature regarding relationships between delirium and cognitive impairment. Psych Info and Medline searches and investigation of secondary references for all English language articles on delirium and subsequent cognitive impairment were carried out. Nine papers met inclusion criteria and documented cognitive impairment in patients following delirium. Four papers reported greater cognitive impairment among patients with delirium than matched controls. Four papers reported higher incidence of dementia in patients with a history of delirium. One study found 1 of 3 survivors of critical illness with delirium developed cognitive impairment. The evidence suggests a relationship between delirium and cognitive impairment, although significant questions remain regarding the nature of this association. Additional research on delirium-related effects on long-term cognitive outcome is needed.
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The association between delirium and cognitive decline: a review of the empirical literature.
Jackson JC, Gordon SM, Hart RP, Hopkins RO, Ely EW.
The goal of the researchers is to help practitioners recognize and treat delirium in patients with DSD as early as possible, helping to improve quality of life for the patient.
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The research team included Fick, currently a 2013-2014 visiting scientist at the Institute for Aging Research at Hebrew SeniorLife in Boston, an affiliate of Harvard Medical School; Melinda R. Steis, community health coordinator, Orlando Veterans Affairs Medical Center; Jennifer L. Waller, associate professor of biostatistics, Georgia Regents University, Augusta, Ga.; and Sharon K. Inouye, professor of medicine, Harvard Medical School.
The National Institute of Aging supported this work.
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Victoria M. Indivero
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814-865-9481
Penn State