Consult-Liaison Education Medicine Reading

DSM-5: Delirium.

This post is the most recent addition to my DSM-5 e-mail list. I include it here only because I apparently have a fondness for delirium; it was one of my favorite teaching topics when working with medical students. If you’d like to read my other DSM-5 summaries, let me know.

(724 words = 5 min read)

How rarely, particularly outside of hospital settings, do we remember to think of delirium!

DSM-5 lists five criteria for delirium:

A. There is a disturbance in attention and awareness.

Because people who are delirious have problems with focus and sustaining attention, this means you might find yourself asking the same questions over and over. The delirious patient may end up providing the same answer over and over, even though you’re asking a different question.

Furthermore, if patients have severe inattention, they might not be able to have a conversation with you at all.

B. Delirium develops over a short period of time, typically hours to days. There is a change in baseline attention and awareness. It fluctuates throughout the day.

Attention and awareness often worsen at night (sometimes referred to as “sundowning“).

C. There is also another disturbance in cognition, such as in memory, orientation, language, and perception.

Delirious patients might think that a pair of socks is an opossum (illusion), the nurse is trying to sell his blood (misinterpretation/delusion), or that he can hear the conversations that are happening in the cafeteria (hallucinations/delusions).

D. The disturbances in (A.) and (C.) are not better explained by another pre-existing, established, or evolving neurocognitive disorder. (Having a neurocognitive disorder, however, increases the risk of the development of delirium.)

You also can’t diagnose delirium is someone is comatose. Essential to the diagnosis of delirium is that the patient can respond to “verbal stimulation”.

E. There must also be evidence that the delirium is due to a direct physiological consequence of another medical condition, substance intoxication or withdrawal, or exposure to a toxin, or is due to multiple etiologies.

This means that delirium always has a cause. Your job is to find that cause (or work with someone who can help you find that cause).

There are many specifiers for delirium (which clarify the cause):

(1) substance intoxication delirium
(2) substance withdrawal delirium
(3) medication-induced delirium
(4) delirium due to another medical condition
(5) delirium due to multiple etiologies
(6) acute
(7) persistent (how terrible!)
(8) hyperactive (more frequently recognized, because these are the people who are shouting that they are on a boat and think that the IVs are snakes)
(9) hypoactive (this is often missed because these are the people who seem to be the most “compliant” patients ever)
(10) mixed level of activity

DSM-5 spends a fair amount of time discussing the recording procedures. If you are a consult-liaison psychiatrist, you should look those over.

DSM-5 states that, in hospital settings, delirium usually lasts about one week. Some symptoms, though, persist even after individuals are discharged from the hospital.

Delirium is considered a “great imitator” amongst psychiatrists. People who are delirious can look psychotic, depressed, manic, anxious, or a combination of all four. Delirium also messes with sleep-wake cycles and may manifest more at night because there is less environmental stimulation present.

DSM-5 provides some prevalence numbers:
(1) people in the community: 1-2% (that number ideally should be 0%)
(2) hospitalized people: 6% to 56% (this is not a comforting range)
(3) people who just had surgery: 15% to 53%
(4) people in ICUs: 70% to 87%
(5) people in nursing homes: 60% (yikes!)
(6) people who are at “end of life”: 83%

Thankfully, the majority of people with delirium experience a full recovery, though delirium is a harbinger of death: About 40% of people who are diagnosed with delirium in the hospital are dead within a year. Delirium also increases the likelihood of “institutional placement” and “functional decline”.

In addition to neurocognitive disorders, other risks for delirium include extremes of age, drug use, polypharmacy, a history of falls, and functional impairment.

Delirium is a clinical diagnosis (there is no test for it), though EEGs might show “generalized slowing”.

I have never thought about the differential for delirium, as that is what I always consider first (but that may be due to my past work as a consult-liaison psychiatrist). DSM-5 includes psychotic disorders, acute stress disorder, malingering, factitious disorder, and other neurocognitive disorders in the differential for delirium. Rarely, though, do those conditions have the “waxing and waning” in level of consciousness and attention that is seen in delirium.

I’ll resume sending [DSM-5] posts out after January 1st. May you all recall fond memories from 2013. May 2014 bring you good health, mirth, and ongoing learning.