- More than 7 million hospitalized Americans suffer from delirium each year.
- Among hospitalized patients who survived their delirium episode, the rates of persistent delirium at discharge are 45%, at one month are 33%, at three months are 26%, and at six months are 21%.
- More than 60% of patients with delirium, it goes unrecognized by clinicians.
- Compared to hospitalized patients with no delirium (adjusted for age, gender, race, comorbidity), delirious patients have:
- Higher mortality rates at one month (14% vs. 5%), at six months (22% vs. 11%), and 23 months (38% vs. 28%)
- Longer hospital lengths of stay (21 days vs. 9 days)
- A higher probability of receiving care in long-term care settings at discharge (47% vs. 18%), 6 months (43% vs. 8%), and at 15 months (33% vs. 11%)
- A higher probability of developing dementia at 48 months (63% vs. 8%) (American Delirium Society, 2013)
Although rare in younger people, the condition can be found in as many 0.5% in those aged between 18 years and 55 years, and about 1% of those aged between 56 years and 85 years. The greatest incidence of delirium occurs in those older than 85 years, at more than 13%. Delirium is also present in about 15% to 20% of patients who are admitted to hospital (Robertson, 2015).
Not only is delirium a serious issue for patients, family, and care providers, it costs the U.S. healthcare system $182 billion each year (Inouye et al., 2014).
What’s more, delirium is preventable in as many as 40% of cases, adding to its importance as a public health priority and an opportunity for containing healthcare costs (Inouye et al., 2014).
While delirium has been noted for thousands of years, it can be maddeningly difficult to recognize because its symptoms are found in many other conditions, for example, dementia or depression (Inouye et al., 2014; Wetherell & Jeste, 2003). Unfortunately, despite the prevalence of delirium and the burden on our healthcare system, it continues to go undiagnosed (Teodorczuk et al., 2012).
I get delirious whenever you’re near
Lose all self-control, baby just can’t steer
Wheels get locked in place
Stupid look on my face
Prince, “Delirious” (1982)
Delirium is a condition hallmarked by rapidly changing mental states. Confusion, behavioral changes, and even loss of consciousness can occur (NIH, Medline Plus, 2015).
The term delirium literally means, “out of the track,” and was first used by Aulus Cornelius Celsus (c. 25 B.C.– c. 50 A.D.), a Roman scientist, to describe either states of agitation or excessive somnolence (Cerejeira & Mukaetova-Ladinska, 2011). Over time the term delirium was used to designate reversible states of acute brain dysfunction, associated with fever or medical and/or surgical conditions (Cerejeira & Mukaetova-Ladinska, 2011).
- A disturbance of consciousness (ie, reduced clarity of awareness of the environment) with reduced ability to focus, sustain, or shift attention
- A change in cognition (such as memory deficit, disorientation, or language disturbance) or the development of a perceptual disturbance that is not better accounted for by a preexisting, established, or evolving dementia
- A disturbance develops over a short period of time (usually hours to days) and tends to fluctuate during the course of the day
- There is evidence from the history, physical examination, or laboratory findings that the disturbance is caused by the direct physiologic consequences of a general medical condition (American Psychiatric Association, 2013)
Another foundational reference, the International Classification of Diseases-10, or ICD-10, describes delirium not due to alcohol or other psychoactive substances as an
etiologically nonspecific organic cerebral syndrome characterized by concurrent disturbances of consciousness and attention, perception, thinking, memory, psychomotor behavior, emotion, and the sleep-wake schedule. The duration is variable and the degree of severity ranges from mild to very severe. (World Health Organization, 2010)
Adding to its complexity, delirium can also manifest itself with three different levels of consciousness: hyperactive, hypoactive, or mixed. Patients with hyperactive delirium can appear agitated, hypervigilant, irritable, with lack of concentration and perseveration (the uncontrollable repetition of a word, phrase, or gesture). Hypoactive delirium can present with diminished alertness, absence of or slowed speech, hypokinesia, and lethargy. Mixed delirium, as the name implies, includes manifestations of both hyperactive and hypoactive delirium (Cavallazzi et al., 2012).
I know you might find this hard to believe, but I’m a writer. I know this may sound crazy, but I created this whole town!
Jack Gable, Delirious (1991)
As we said in the previous section, delirium can present itself in myriad ways. Let’s take a closer look at some of the more specific symptoms. The constellation of delirium symptoms can fall into three categories: cognitive, behavioral, and physiologic.
- Inability to sustain attention
- Impaired short-term memory
- Impaired visual and/or spatial ability
- Reduced level of consciousness, especially at night
- Perseveration (uncontrolled repetition, such as a word or gesture) (Cavallazzi et al., 2012; Medline Plus, 2014a)
- Sleep-wake cycle disturbance
- Delusions (Cavallazzi et al., 2012)
- Hypertension (Cavallazzi et al., 2012; MedLine Plus, 2014a)
Tremors, elevated heart rate, and elevated blood pressure are seen especially in those experiencing alcohol withdrawal syndrome (Cavallazzi et al., 2012).
Source: U.S. Department of Veterans Affairs, 2012. https://www.youtube.com/watch?v=M4wsPTtGeIc