Would You Recognize Acute Delirium?

Kevin Biese, MD; Adam Perry, MD


March 28, 2018

Delirium, Depression, Dementia: Which of the Three D's Is It?

Delirium is an acute change in mental status not attributable to pre-existing or evolving dementia. It is defined by acute or fluctuating mental status change with inattention and altered level of consciousness and/or disorganized thinking. Present in approximately 10% of older adults in the ED, it is not diagnosed in the majority of cases.

Underrecognition has significant adverse consequences, as delirium is associated with longer hospital lengths of stay, increased mortality, and accelerated cognitive and functional decline.[1] Suddenly worsening dementia is likely delirium—and delirium is often caused by an acute medical illness, medication, or pain.

The American College of Emergency Physicians 2014 Geriatric Emergency Department Guidelines, which were endorsed by The American Geriatrics Society, Emergency Nurses Association, and the Society for Academic Emergency Medicine, recommend screening older adults for delirium using a validated instrument, such as the Brief Confusion Assessment Method. This patient demonstrates delirium by acute alteration in mental status, inattention on "months of the year backwards," and altered level of consciousness as measured on the Richmond Agitation Sedation Scale.

Clinical Course

During her stay in the ED, the patient becomes more restless and resistant to care, twice getting out of bed and walking out of the room requesting discharge. She does not demonstrate an understanding of why she is in the ED and the rationale for evaluation and treatment.

A call to the nursing facility provides important context. Her physician relates that she has been in the skilled nursing facility for postacute rehabilitation for 10 days following an admission at a nearby hospital for congestive heart failure exacerbation. Prior to hospitalization, she had been living independently in an apartment. Until this behavior change, which began approximately 3 days ago, she had been awake, alert, cooperative, and participating in rehabilitation. During her recent hospitalization, furosemide dose was increased to 80 mg daily from 10 mg. Her baseline creatinine is 0.8 mmol/L.

One month ago, she was diagnosed with mild dementia and placed on donepezil. Her daughter, who holds healthcare power of attorney, lives locally and visits daily. She has had no falls, nor does she suffer from fever or respiratory, cardiac, gastrointestinal, urinary, or localizing neurologic symptoms.


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