Looking at the Latin origin of the word “delirium” we get a colourful image of what delirium really is:
The origin of the word “delirium”
- “Lira” – Latin for “furrow”
- “Delirare” means “to jump out of the furrow while ploughing”
- Delirium is a sudden temporary change from the normal steady state that has a specific cause (e.g. your plough hits a rock) and that can be corrected.
Click on the tabs below to see other definitions for delirium, and a mnemonic for remembering the key characteristics of delirium.
Simple Definition of Delirium
An acute confusional state caused by some medical or pharmacological trigger.
Another way to think of it is as a type of organ failure – “Acute Brain Failure.”
We are familiar with the concept of acute renal failure – the kidneys stop doing their job of taking blood, filtering out waste and retaining important electrolytes. Another example is acute heart failure – the pump stops doing is job of pumping blood to organs. We are aware that the main risk factor for ARF or AHF are chronic insufficiency.
The purpose of the brain is to take in information from the environment, process it, and formulate an appropriate response. When a patient has delirium, the brain is acutely unable to process information and stimuli appropriately. The primary risk factor for delirium is a brain that has dementia or “chronic insufficiency.”
- Disturbance of consciousness with reduced ability to focus, sustain, or shift attention
- Change in cognition that is not better accounted for by a pre-existing, established, or evolving dementia
- Development over a short period of time (usually hours to days) and disturbance tends to fluctuate during the course of the day
- There is evidence from the history, physical exam, or lab findings that the disturbance is caused by the consequences of a general medical condition
Key Characteristics of Delirium
AIDA – This mnemonic is helpful for remembering the key characteristics of delirium based on the DSM-IV definition:
A– Acute and fluctuating
D– Disorganized thinking: incoherent, rambling,
A-Altered level of consciousness: drowsy, lethargic, stuporous, hyper-alert, agitated