Delirium is also known as acute confusional state, altered mental status, and toxic metabolic encephalopathy, among more than 30 descriptive terms. Delirium can be thought of as acute brain failure and is the final common pathway of multiple mechanisms, similar to acute heart failure. The official definition of delirium in the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5), requires a disturbance in attention and awareness that develops acutely and tends to fluctuate. The pathophysiological mechanisms of delirium remain poorly understood; leading models include neurotransmitter imbalance and neuroinflammation.
Diagnostic Criteria for Delirium
DSM-5
The presence of delirium requires all the criteria to be met:
- Disturbance in attention and awareness
- Disturbance develops acutely and tends to fluctuate in severity
- At least one additional disturbance in cognition
- Disturbances are not better explained by a preexisting dementia
- Disturbances do not occur in the context of a severely reduced level of arousal or coma
- Evidence of an underlying organic cause or causes
Confusion Assessment Method (CAM)
The presence of delirium requires features 1 and 2 and either 3 or 4:
- Acute change in mental status with a fluctuating course (feature 1)
- Inattention (feature 2)
- Disorganized thinking (feature 3)
- Altered level of consciousness (feature 4)
References:
- Marcantonio ER. Delirium in Hospitalized Older Adults. N Engl J Med. 2017 Oct 12;377(15):1456-1466. [Medline]
- Setters B, Solberg LM. Delirium. Prim Care. 2017 Sep;44(3):541-559. [Medline]
Created Nov 16, 2017.
