The modern concept of delirium or an acute confusional state has been around for decades, but physicians are still confused about it. A recent review article in the New England Journal of Medicine summarizes what we know about delirium: what it is, how to treat it, and how to try to prevent it. “Delirium in Hospitalized Older Adults,” as the title says, does not address delirium outside the hospital, i.e. in the skilled nursing facility, where it is even less well-recognized, but despite this limitation it is a welcome update of an important topic.
Older patients—most of the studies define “older” in this context as at least 70—are at high risk of developing the acute onset of confusion after they are admitted to the hospital. Lumping all older people together, regardless of age or reason for admission, roughly one-third will become delirious. Among people who have certain operations such as hip fracture repair or cardiac surgery, the rate is more like 50 percent, and among older patients in the ICU on a ventilator, it rises to 75 percent. What’s particularly striking is that once delirium strikes, it’s hard to get rid of. At the time they are discharged, nearly half of all patients who got delirium in the hospital still have it, and a month later one-third still meet the criteria for delirium. It’s not always “hyperactive delirium,” the agitation we usually think of when we hear the word delirium; in fact, nearly 75 percent of the time it’s the opposite, or “hypoactive delirium,” a more insidious, quieter form of the disorder.
The article goes through the major triggers of delirium, with medications (especially sedatives, opioid pain medications and other mind-altering substances) at the head of the list. Out-of-whack blood chemistries (technically known as electrolyte disturbances) and infection are two other leading offenders, but the bottom line is that almost anything can result in delirium, from a heart attack to severe constipation. Treatment consists primarily of removing or curing the underlying precipitant—for example, getting rid of the implicated medicine, limiting the heart attack damage, or getting the bowels moving. The author is at pains to tell us that among twelve randomized controlled trials of antipsychotic medications in the treatment of delirium, none of them resulted in decreasing the severity or duration of delirium, none of them lowered mortality rates or length of stay in the hospital. Nonetheless, he indicates that antipsychotic drugs may be prescribed if needed to control particular symptoms.
Most interesting are the reminders about what works best to prevent delirium. The gold standard is still the 1999 HELP study (Hospital Elder Life Program) that used trained volunteers to make sure older patients wear their glasses and their hearing aids and that they get a back rub rather than a sleeping pill if they have trouble sleeping at night. Another approach that also makes a difference is a proactive geriatric consultation. Especially when initiated on a surgical service, this can assure that older patients are not prescribed sedating medications, that they receive round-the-clock acetaminophen whenever possible instead of as needed opioids, and that they get out of bed and moving as soon as possible. A related approach that the author doesn’t mention is use of the ACE unit (Acute Care for the Elderly), a specially designed inpatient unit that builds anti-delirium measures into its mode of operation.
But what’s important to emphasize is that even the best delirium prevention strategies are only moderately successful. Delirium is a nasty disorder: it is extremely unpleasant, it’s dangerous, and it lingers. Some people never recover fully, some die. For older people who have some degree of cognitive impairment, those who have significant trouble carrying out daily activities, and those with multiple problems on many medications, the best approach may be to avoid the hospital altogether.