Delirium

Question 1

What is delirium?

Answer 1

Reversible, acute-onset condition that develops over a short period of time and results in transient global cognitive dysfunction. Can have many different causes.

Question 2

What are core features of delirium?

Answer 2

1) Disturbance in cognition - reduced ability to direct, focus, sustain, or shift attention. Patients are typically highly distractible, unable to maintain stream of thought or action.
2) Fluctuations in level of attention and orientation. Periods of somnolence may be followed by excessive alertness/agitation (positive/hyperactive and negative/hypoactive elements of delirium). Disturbances in mood and sleep-wake cycle are common.
3) Reduced awareness and disorders of perception (including illusions, hallucinations, and delusions). Hallucinations are usually visual.
4) Changes in psychomotor behavior - marked by increased motor activity, restlessness, lethargy, lack of initiation, and slow reaction time.

Question 3

What is the difference between delirium and encephalopathy?

Answer 3

Delirium is an acute state.
Encephalopathy is a nonspecific term to describe any medical condition affecting brain function and can describe both acute and chronic changes.

Question 4

What is the mnemonic for understanding etiology of delirium?

Answer 4

I WATCH DEATH.
I = infection
W = Withdrawal
A = acute metabolic (diabetic ketoacidosis, organ failure, etc.)
T = Trauma (TBI)
C = CNS pathology (abscess, tumor, stroke, etc.)
H = Hypoxia
D = Deficiencies in nutrition (B12, folate, thiamine, niacin)
E = endocrinopathies (hypothyroidism, hyperparathyroidism, hyperglycemia, etc.)
A = acute vascular
T = toxins/drugs
H = heavy metals (lead, mercury)

Question 5

Which neurotransmitter systems are involved in delirium?

Answer 5

Decrease in acetylcholine (cholinergic deficiency hypothesis) contributes to reduced attention and memory.
Excess dopamine can cause hallucinations.
Overexcitation of serotonergic systems may cause hallucinations. Use of multiple serotonergic agents can result in serotonin syndrome (i.e., includes AMS, agitation, myoclonus, diaphoresis, tremor, diarrhea, incoordination, and fever) - if left untreated, patient can die.

Question 6

What are risk factors for delirium?

Answer 6

1) Pre-existing brain disease or cognitive impairment results in reduced brain or cerebral reserve which lowers the patient’s tolerance threshold – this explains why individuals with pre-existing dementia are at higher risk of developing delirium following minor surgical events.
2) Age. Aging brain has altered vasculature, decreased cholinergic activity, and is less able to tolerate or adapt to physiological changes (like a UTI).
3) Comorbid physical problems, such as sleep deprivation, sensory impairment, dehydration, pain, etc. also increase vulnerability.
4) Medical comorbidities/uncontrolled conditions increase vulnerability (e.g., HTN, DM)

Question 7

Postoperative states can be a precipitating factor of delirium. Describe one postoperative complication that can lead to delirium.

Answer 7

Hyponatremia following medical procedure - which is when blood sodium levels are too low. Can be caused by kidney and heart failure, and cirrhosis.

Acute injuries or medical procedures can result in metabolic or other complications that can lead to confusion. For example coronary artery bypass graft (CABG) and surgical repair of long bone fractures have been associated with cerebral fat emboli (i.e., microembolism) leading to delirium and in some lead to permanent impairment. Fat emboli are fat particles that may get released from bone marrow and then reach the brain.

Question 8

What are common causes of delirium in young and older adults?

Answer 8

Drug abuse is common cause of delirium in young adults. Infection and medication side effects lead to delirium in older adults.

Question 9

How prevalent is delirium in older adults that are hospitalized?

Answer 9

About 15% of older adults 85 years and older experience delirium.
Large proportion of older adults experience delirium after vascular operations, hip surgery, or CABG (with the latter may be linked to emoblic shower, microembolism, or cerebral fat emboli)

Question 10

Which is more common, hyperactive or hypoactive delirium?

Answer 10

Hypoactive delirium, especially in older adults.

Question 11

What are complications of delirium?

Answer 11

Increased impulsivity, picking at clothes or skin, and agitation can lead to unintentional injury (e.g., falls, self-extubation, pulling at lines, tubes)

Question 12

What are the 2 different courses of delirium?

Answer 12

1) abrupt or immediate onset - can occur with moderate to severe TBI or stroke
2) Slow onset or fluctuating course - can develop or hours or days (with developing metabolic disturbance such as hyponatremia due to organ failure). Symptoms can wax and wane with islands of lucidity.

Question 13

How is delirium different from schizophrenia/other psychotic disorders?

Answer 13

For patients with chronic psych conditions, consciousness and cognition are not as severely impaired as in delirium.
For patients with chronic psych conditions, hallucinations and delusions are typically consistent and systematic - but in delirium and LBD that is not the case

Question 14

What is Capgras syndrome?

Answer 14

a delusional belief that a person has been replaced by an imposter or duplicate. often associated with frontal system dysfunction such as progressive dementia (and schizophrenia). usually not observed in delirium.

Question 15

What is reduplicative paramnesia?

Answer 15

a delusional belief that a place has been replaced or duplicated. typically associated with conditions causing severe dysfunction such as dementia or delirium.

Question 16

How are patients with delirium of unknown etiology treated?

Answer 16

Often receive thiamine followed by glucose - because they are safe, easy to administer, and cover a host of potential problems. Also important for patients to get good hydration, nutrition, and airway management.

Question 17

What happens to the sleep wake cycle in delirium?

Answer 17

often reversed - with pronounced lethargy during the day and agitated arousal at night. patients should get proper assistance with restoring healthier sleep cycle by medication, changing environment, and getting out of bed during the day.

Question 18

What interventions are helpful for patients with delirium?

Answer 18

Frequent orientation cueing, reassurance, use of large clocks and calendars, placing familiar objects in the room, having quiet and well lit room, having windows, having glasses and hearing aids available, avoidance of restraints, having familiar faces present, increasing movement.

Question 19

What medications might be used to manage delirium?

Answer 19

Neuroleptics to address hallucinations

Benzos for alcohol withdrawal

Question 20

What drugs commonly used with elderly can lead to delirium?

Answer 20

Digoxin, warfarin, codeine, ranitidine, and prednisolone.
Medication classes commonly associated with delirium include tricyclic antidepressants, anticholinergics, benzos, corticosteroids, sedative hyponotics, anticonvulsants, antiparkinsonian drugs, antinflammatories.

Question 21

What are considerations for treating patients with delirium?

Answer 21

1) Require 24 hour supervision and monitoring. Many are on an ICU or have 1:1 sitters. Restraints may be used as last resort.
2) Can’t drive.
3) After delirium, can be phased back in normal school or occupational responsibilities.
4) Decisional capacity is impaired. Temporary guardian and conservator is recommended or required. Can’t make complex informed decisions.
5) Eliminate anticholinergic medications and dopaminergic agents. Antipsychotic medications may help reduce agitation, hallucinations, and promote normal sleep.
6) Patients are typically dependent on others for BADLs and IADLs. They are often unaware of their functional declines and claim that they can return to living independently.
7) Patients may need inpatient rehab to receive continued environmental management, receive PT, OT, Speech Therapy, and recreational therapy in a structured controlled environment.

Question 22

How long does delirium last?

Answer 22

It can last for weeks and even months after the primary medical conditions underlying delirium have been resolved.

Question 23

What is hyponatremia?

Answer 23

An electrolyte disturbance in which sodium level is low. Occurs when water accumulates in body at faster rate than it can be excreted (like congestive heart failure). Can lead to cerebral edema. About 25% of cases are postoperative.

Question 24

What is hypernatremia?

Answer 24

An electrolyte disturbance in which sodium level is high. Usually caused by dehydration or conditions that lead to excessive water loss, like diarrhea. Can cause cerebral dehydration resulting in delirium.