Dr. Sharon Inouye Presents Lecture on Delirium in the Elderly
In addition to saving older adults’ lives, the prevention and treatment of delirium may lower their risks of lasting cognitive impairment, Sharon K. Inouye, MD, MPH, told an audience of more than 1500 geriatrics healthcare professionals during the AGS’ Annual Scientific Meeting in May. Dr. Inouye, the winner of the AGS’ 2010 Edward Henderson State-of-the-Art Award, delivered the meeting’s Henderson State-of-the-Art Lecture, which focused on her seminal research concerning delirium and functional decline in older people. “Delirium may provide the unique opportunity for early intervention and prevention of permanent cognitive damage,” Dr. Inouye noted.
The Director of the Aging Brain Center, Hebrew SeniorLife, and a Professor of Medicine at Harvard Medical School, Dr. Inouye has published more than 140 papers on delirium—an acute, temporary change in cognition characterized by relatively rapid onset and variable symptoms, including difficulty maintaining attention. Dr. Inouye also holds the Milton and Shirley F. Levy Family Chair at Hebrew SeniorLife’s Institute for Aging Research.
In addition to developing a highly effective screening protocol for delirium—the Confusion Assessment Method (CAM)—she and colleagues have also developed a multifaceted intervention strategy, the Hospital Elder Life Program (HELP), to prevent delirium by targeting risk factors for the syndrome. In the first study to show that a substantial number of cases of delirium are preventable, the intervention reduced risks of delirium by nearly 40% and cut healthcare costs significantly. The HELP model, which has also been shown to substantially reduce the incidence of falls in the hospital among seniors, is now being disseminated internationally. It is in use at more than 60 sites in six countries.
Often overlooked, delirium is common among older adults in institutional settings, Dr. Inouye noted in her lecture. The prevalence of delirium among those admitted to the hospital is as high as 24% and in-hospital incidence rates can reach 65%. Delirium is associated with high mortality both during hospitalization and post-discharge. One year after discharge, the mortality rate ranges from 35% to 40%. Hospital costs alone total $8 billion nationwide. And the tab for post-hospital costs are even higher—roughly $100 billion for institutionalization, rehabilitation, home care services, and caregiver burden. Total costs attributable to delirium range from $16,000 to $64,000 per patient.
“With the aging of the population, this is a problem that will continue to increase unless we can find good ways to manage it, and we can’t manage delirium and reduce complications unless we can recognize it,” said Dr. Inouye, who cited a study finding that only 31% of delirium cases among older adults were recognized.
Understanding, Preventing, Diagnosing, and Managing Delirium
Delirium is much more likely to be overlooked in patients with advanced age, vision impairment, the hypoactive form of delirium (which manifests as sleepiness), and dementia, Dr. Inouye explained. CAM, which has a sensitivity rate of 94% and a specificity rate of 89%, focuses on key characteristics of delirium: acute onset and fluctuating course; inattention; disorganized thinking; and altered levels of consciousness. A diagnosis of delirium requires the presence of the first two characteristics and either the third or the fourth, she noted, adding that CAM can provide a quick and accurate diagnosis and has helped to improve the recognition of delirium worldwide. “[Even so] we don’t recommend using it as a diagnostic tool, but rather, as a screening tool and then confirming the diagnosis with other means,” added Dr. Inouye, who suggests follow-up with a formal cognitive test such as the Mini-Cog, Montreal Cognitive Assessment, or Modified Mini-Mental State Examination. “You don’t want to rely just on the features [in CAM]—they’re supportive rather than diagnostic because they can have both false positives and negatives.”
In the majority of cases, delirium is a multifactorial process resulting from the interaction of predisposing factors at baseline and precipitating factors that arise during hospitalization, Dr. Inouye explained. Leading predisposing factors include vision impairment, severe illness, cognitive impairment, and dehydration. Leading precipitants include the use of physical restraints or bladder catheters, malnutrition, and the introduction of more than three new medications in a 24-hour period, which will also boost older patients’ risks of delirium significantly.
For older adults with cognitive, vision, or hearing impairment, or multimorbidity, “even a single dose of a sleeping med may be enough to throw them into delirium,” added Dr. Inouye. Medications that put older patients at particularly high risk of delirium include not only sedative-hypnotics but also narcotics, anticholinergic drugs, and cardiac and antihypertensive drugs. In light of this, frequent reviews of medication lists and minimization of psychoactive and other medications should be priorities, said Dr. Inouye.
There are often alternatives to medications, she emphasized. To help an older patient sleep, for example, she recommends the following nonpharmacological sleep protocol: a 5-minute back rub; a warm drink such as milk or herbal tea; relaxation tapes; and an hour to assess the effect. This approach has been shown to reduce the use of sleep medications by as much as 54%, Dr. Inouye reported. Discouraging naps, scheduling medications and vital signs checks for the daylight hours, and keeping the patient’s room dark and as quiet as possible at night can also help.
Electrolyte imbalances, major organ system disease, infections, injury, an unfamiliar environment, and withdrawal from benzodiazepines and alcohol are other common precipitants of delirium. Clinicians should keep the latter in mind and speak with family members about the patient’s use of alcohol and sleeping medications to address this possibility, Dr. Inouye said.
“The reason delirium is more common in older patients is because they’re more vulnerable,” she explained. “Addressing the multi-factorial etiology is key to managing delirium.” Efforts to prevent delirium among vulnerable elders are essential, Dr. Inouye noted. The Delirium Prevention Program developed at Yale—where she was Director of both the Yale Mentored Clinical Research Scholars Program and the Patient-Oriented Research for the Yale Investigative Medicine Program and Co-director of the Yale Program on Aging/Claude D. Pepper Older Americans Independence Center—targets risk factors for delirium. It calls for the following, as needed: reality orientation; therapeutic activities; the nonpharmacologic sleep protocol and sleep enhancement strategies; early mobilization; the provision of vision and hearing aids, and sufficient liquids to prevent dehydration. This approach, which has been shown to lower risks of delirium and lengths of stay and to reduce costs, is being disseminated through the HELP program.
Clinicians who suspect delirium should, after performing a brief cognitive assessment and determining an older patient’s CAM rating, search for underlying contributors. Conducting a physical and neurological examination, checking vital signs, asking about alcohol and benzodiazepine history, and reviewing mediation lists—both current and preadmission—are appropriate. So is a targeted laboratory workup to check for occult infection and metabolic derangements. Neuroimaging may be necessary for patients with a history of recent falls, head trauma or signs of head trauma, focal neurological changes, fever and acute mental status changes, suspected encephalitis, and no identifiable etiology.
“So, when do you need to use the pharmacological approach [to managing delirium]?” Dr. Inouye asked. “Reserve this for patients with severe agitation that will interrupt essential medical therapies, such as intubation, or for patients who pose a safety hazard for themselves or others.” The medication of choice for such patients is haloperidol, which is the only drug shown effective in shortening delirium in randomized, controlled clinical trials, she explained, urging those in the audience to avoid the IV form of the drug to start with very low doses.
“All of this is only the tip of the iceberg regarding what we need to know about delirium,” said Dr. Inouye, who ended the lecture by outlining further research she’d like to tackle in the near future. Research to identify more effective ways of managing delirium after it occurs is essential, she noted. So is research examining whether it is possible to build cognitive reserve—through education, diet, or activity—that might protect against delirium. Additional research examining the pathophysiology of delirium is also needed, she added.
“Does delirium lead to dementia?” she concluded. “We don’t know for sure, but early evidence suggests that it may. What we do know is that delirium does provide the unique opportunity for early intervention to forestall the onset of permanent cognitive damage.”
Dr. Spivack is Associate Clinical Professor of Medicine, Columbia University, New York, NY; Consultant in Geriatric Medicine, Greenwich Hospital, Greenwich, CT; and Medical Director, LifeCare, Inc., Westport, CT.
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