1. Delirium is characterized by a disturbed consciousness and change in cognition that develops over a short period of time; onset is acute and symptoms occur rapidly.
2. Delirium is an acute and debilitating decline in attention-focus, perception, and cognition that produces an altered form of semi-consciousness.
3. It is a systemic syndrome caused by a chemical or disease-process which is disrupting the neurons of the cerebral cortex.
4. Though hallucinations and delusions are often present, the symptoms of delirium are clinically distinct from those induced by psychosis or hallucinogens.
5. Delirium itself is not a disease, but rather a clinical syndrome (a set of symptoms), which result from an underlying disease or new problem with mentation
6. Evidence from the client’s history, physical examination, or diagnostic testing indicates that the delirium is a direct physiologic consequence of a general medical condition, substance intoxication or withdrawal, use of medication, or toxin exposure or a combination of these factors.

B. Common Symptoms of Delirium:

1. Impaired consciousness and attention, disorientation
2. Disorganized thinking and rambling speech
3. Disturbance in the sleep-wake cycle, such as daytime sleepiness and nighttime agitation
4. Psychomotor changes (hyperactivity and agitation, or hypoactivity and somnolence)
5. Misinterpretation of situations and reality, illusions, and hallucinations
6. Labile mood (rapid, unpredictable shifts from one emotional state to another).

C. Types of Delirium:

1. In delirium due to a general medical condition, multiple medical conditions can be associated with delirium; acute or chronic illnesses, hormonal and nutritional factors, sensory impairments, and various medication as well as surgical procedures can all contribute.
2. In substance-induced delirium and substance withdrawal delirium, the client’s history, physical examination and diagnostic study findings indicate the delirium is associated with substance use.
3. In delirium due to multiple etiologies, several medical conditions or a combination of substance use and medical conditions is evident.
4. Delirium not otherwise specified is the DSM-IV TR classification applied when insufficient evidence exists to establish a definitive etiology.

D. Causes of Delirium:

1. Delirium is complex and usually multifactored.
2. Delirium may be caused by severe physical illness, or any process which interferes with the normal metabolism or function of the brain.
3. The following risk factors are associated with delirium:
   • Advanced age
   • Preexisting illness
   • Infection and/or electrolyte and metabolic imbalance
   • Bone fractures
   • Brain damage or dementia.

E. Delirium Treatment:

1. Treatment of delirium is achieved by treating the underlying dysfunction cause, or in many cases, the causes (plural), as delirium is often multi-factorial.
2. Treatment usually occurs in an acute care medical-surgical setting.
3. The client typically undergoes a comprehensive diagnostic assessment, and physiologic symptoms are readily treated.
4. Objectives of treatment include:
   • Identification of the immediate cause
   • Correction of the underlying cause
   • Symptoms management
   • Supportive and safety measures.