Lecture 5 Neurology Theme - Delirium

Question 1

What is delirium?

Answer 1

An acute onset syndrome with disturbance in attention, awareness and cognition.
There is normally an underlying cause.

Question 2

Describe the epidemiology of delirium.

Answer 2

Becoming more and more common - especially in hospitals and ICU.
People with dementia have a 5-10 fold increase of developing delirium.
Affects 30% of elderly hospital patients.
2/5 people die after 12 months and 20% don’t return to baseline.

Question 3

What are some differences between delirium and dementia?

Answer 3

Delirium has an acute onset, a duration of days/weeks, presents with distracted attention and a persons level of consciousness can be increased, decreased or unchanged.
Dementia has an insidious onset, duration of months/years, normal attention and level of consciousness is usually normal.

Question 4

What does the multifactorial model for delirium show?

Answer 4

Trigger events need to be major to make healthy people develop delirium whereas high vulnerability people can be triggered by a minor event.
Healthy people can revert back to normal after the trigger event quicker.

Question 5

Describe the prognosis for delirium.

Answer 5

Can be slow to resolve.
40% persist for 2 weeks
33% persist for 1 month
20% never recover
8-fold increased risk of developing dementia within 3 years.

Question 6

What cognitive assessment tools can be used to help diagnose delirium?

Answer 6

AMT (abbreviated mental test)
CAM (confusion assessment method)
SQiD and 4AT

Question 7

Describe AMT.

Answer 7

Abbreviated mental test.
Commonly used.
Scores of < 8 out of 10 should prompt further evaluation.

Question 8

Describe CAM.

Answer 8

Confusion assessment method.
Nearly 100% sensitive and 95% specific for delirium if acute onset with a fluctuating course, inattention, disorganised thinking and altered level of consciousness are met.
Tools may not be sensitive to older patients because of sensory impairment, dementia or pain and anxiety.

Question 9

Describe SQiD and 4AT.

Answer 9

Is the patient more confused than before is the SQiD question.
4AT = short delirium detection tool assessing the patient or alertness ask about age, DOB, current place and year and get people to do attention tasks such as recalling the months backwards.
A score of 4+ indicates delirium.

Question 10

What is some non-pharmacological management for delirium?

Answer 10

Familiar faces or objects from home being around is helpful.

Question 11

What is the ABC approach?

Answer 11

Antecedent (things that trigger different behaviours), Behaviours (what is the patient trying to achieve) and Consequences (is it causing harm).
Is using restraint/sedation a greater harm than the behaviour?

Question 12

Describe drug management for delirium.

Answer 12

Haloperidol and lorazepam = main drug treatments.
Indications for using sedative drugs are rapid tranquillisation of the patient where there is an immediate risk of harm or to short-term control distress - given in small doses and discontinued shortly.

Question 13

What are the main predisposing factors to developing delirium?

Answer 13

Older age (>70)
Dementia
Functional disabilities
Male gender
Poor vision and hearing
Mild cognitive impairment

Question 14

What are some precipitating factors to developing delirium?

Answer 14

Medications (39% of delirium cases)
Surgery
Anaesthesia
Hypoxia
Untreated pain
Acute illness
Infections

Question 15

Describe the role of increased age in developing delirium.

Answer 15

Changes associated with age lead to a diminished physiological reserve and increased vulnerability to physical stress and illness.
Some changes include decreased brain blood perfusion, increased neuron loss, changes in the proportion of stress regulating neurotransmitters.

Question 16

Describe the role of neuroinflammation in developing delirium.

Answer 16

Peripheral inflammatory insults damage cell to cell endothelial adhesions at the BBB.
The increased endothelial permeability promotes inflammation in the CNS causing further damage, ischemia and neuronal death.

Question 17

Describe the role of ROS in developing delirium.

Answer 17

ROS and RNS are a mediator of cellular damage.
The CNS is particularly vulnerable to ROS due to its high lipid content and low antioxidant capacity.

Question 18

Describe the role of circadian rhythm dysregulation in developing delirium.

Answer 18

Disruption in sleep duration and architecture and melatonin secretion levels leads to dysfunction of many systems.
Melatonin can affect regulation of sleep-wake cycles, glucose regulation, core body temp, antioxidant defences and immune system response.

Question 19

Describe the role of neurotransmitter imbalance in developing delirium.

Answer 19

Delirium associated with decreased acetylcholine and increased dopamine activity.
The dopaminergic and cholinergic pathways overlap in the brain and their balance is vital to normal brain function.

Question 20

Describe the role of the neuroendocrine system in developing delirium.

Answer 20

Increased glucocorticoid release in response to physiological stress increases the vulnerability of neurons to subsequent damage and impacts the regulation of gene transcription, cellular signalling and glial cell behaviour.

Question 21

What are the 3 main manifestations of delirium?

Answer 21

Hyperactive delirium
Hypoactive delirium
Mixed presentation

Question 22

Describe hyperactive delirium.

Answer 22

Patients present with increased agitation and sympathetic activity.
They can present with hallucinations, delusions and occasionally combative or uncooperative behaviour.

Question 23

Describe hypoactive delirium.

Answer 23

Patients have increase somnolence and decreased arousal.
Hypoactive delirium is dangerous as it is often unrecognised or mistake for fatigue or depression.
It is associated with higher rates of morbidity and mortality.

Question 24

Describe mixed presentation delirium.

Answer 24

Patients fluctuate between hyperactive and hypoactive presentations.

Question 25

What criteria does the CAM have?

Answer 25

acute onset and fluctuating course, inattention, disorganised thinking and altered level of consciousness