1. Delirium

2. Delirium
Early diagnosis and resolution of symptoms are correlated with the most favorable outcomes.
It must be treated as a medical emergency.
Delirium is not a disease but a syndrome with multiple causes.

3. Pathophysiology
Hyperactive delirium -- patients in a state of alcohol withdrawal or intoxication with to phencyclidine (PCP), amphetamine, and lysergic acid diethylamide (LSD).
Hypoactive delirium -- patients in states of hepatic encephalopathy and hypercapnia.
Mixed delirium -- individuals display daytime sedation with nocturnal agitation and behavioral problems.

4. Pathophysiology
The mechanism of delirium still is not fully understood.
Research in these areas still is limited.
The main hypothesis is reversible impairment of cerebral oxidative metabolism and multiple neurotransmitter abnormalities.

5. Mortality/Morbidity
In patients who are admitted with delirium, mortality rates are 10-26%.
Patients who develop delirium during hospitalization have a mortality rate of 22-76%.
In patients who are elderly and patients in the postoperative period, delirium may result in a prolonged hospital stay, increased complications, increased cost, and long-term disability.

6. History
Nursing notes can be very helpful for documentation of episodes of disorientation, abnormal behavior, and hallucinations.
Delirium is mistaken for dementia or depression, especially when patients are quiet or withdrawn.

7. History Main symptoms Clouding of consciousness
Difficulty maintaining or shifting attention
Disorientation
Illusions
Hallucinations
Fluctuating levels of consciousness

8. History Neurological symptoms Dysphasia Tremor
Asterixis in hepatic encephalopathy and uremia
Motor abnormalities

9. Causes DSM-IV classification of delirium
Delirium due to general medical condition
Substance intoxication delirium
Substance withdrawal delirium
Delirium due to multiple etiologies
Delirium not otherwise specified

10. Causes
Some of the other common reversible causes include the following:
Hypoxia
Hypoglycemia
Hyperthermia
Anticholinergic delirium
Alcohol or sedative withdrawal

11. Causes Other causes of delirium include the following: Infections
Metabolic abnormalities
Structural lesions of the brain
Postoperative states
Miscellaneous causes, such as sensory deprivation, sleep deprivation, fecal impaction, urinary retention, and change of environment

12. Workup
Complete blood cell count with differential - Helpful to diagnose infection and anemia
Electrolytes - To diagnose low or high levels
Glucose - To diagnose hypoglycemia, diabetic ketoacidosis, and hyperosmolar nonketotic states
Renal and liver function tests - To diagnose liver and renal failure
Thyroid function studies - To diagnose hypothyroidism
Urine analysis - Used to diagnose urinary tract infection
Urine and blood drug screen - Used to diagnose toxicological causes
Thiamine and vitamin B-12 levels - Used to detect deficiency states of these vitamins
Tests for bacteriological and viral etiologies - To diagnose infection
Sedimentation rate
Drug screen including alcohol level

13. Workup – Imaging studies
Neuroimaging
Perform CT scan of the head.
Magnetic resonance imaging (MRI) of the head may be helpful in the diagnosis of stroke, hemorrhage, and structural lesions.
Electroencephalogram
Chest x-ray is used to diagnose pneumonia or congestive heart failure

14. Workup – Other Tests
Lumbar puncture is indicated when CNS infection is suspected as a cause of delirium or when the source for the systemic infection cannot be determined.
Pulse oximetry is used to diagnose hypoxia as a cause of delirium.
Electrocardiogram is used to diagnose ischemic and arrhythmic causes

15. Treatment
When delirium is diagnosed or suspected, the underlying causes should be sought.
Despite every effort, no cause for delirium can be found in approximately 16% of patients.
Components of delirium management include supportive therapy and pharmacological management.