Delirium

Question 1

Define delirium

Answer 1

An acute reversible confusional state - fluctuating encephalopathic syndrome of inattention, impaired consciousness and perception.
Develops over hours to days.

Question 2

What are the three main types of delirium?
How do they present?

Answer 2

Hyperactive - inappropriate behaviour, hallucination, wandering or agitation
Hypoactive - lethargy, reduced concentration/appetite, withdrawn
Mixed - symptoms of both
All types are confused.

Question 3

What are some predisposing factors for delirium? (Inc vulnerability)

Answer 3

1. Age - over 65yrs
2. Long term cognitive impairment - reduced baseline
3. Sensory impairment - visual or hearing, inc sensory isolation
4. Co-morbidities - cardiac, renal or hepatic
5. History of or current alcohol abuse
6. Fraility
7. Significant injuries

Question 4

What are some precipitating factors for delirium? (triggers)

Answer 4

1. Infections - particularly CAP/UTI Strep.pneumoniae or E.coli
2. Drugs - anticholinergics, sedatives, opiods
3. Surgery/ general anaesthesia - post-operative delirium
4. Metabolic abnormalities - electrolyte imbalances, hypoxia, hypercapnia, hypo/hyperglycaemia
5. Severe and uncontrolled pain

Question 5

What are the different theories of delirium?

Answer 5

Neurotransmitter Imbalance Theory - cholinergic deficiency and dopamine excess
Inflammatory response theory - systemic to cerebral inflammation, cytokines cross BBB and active microglia causing neuronal dysfunction
Oxidative Stress theory - inc production of ROS disrupts neuronal cell function
Neuroendocrine alteration theory -aberrant response to cortisol cause hippocampal damage
BBB disruption - from inflammation, oxidative stress or direct injury - allows neurotoxic substances to enter the brain and cause neuronal dysfunction

Question 6

What are the key presentations of delirium?

Answer 6

Attentional deficits - shifting or poorly sustained, struggle to follow conversation
Altered consciousness - can have periods of lucidity
Cognitive impairment - mainly short term memory, orientation and language
Altered perception - hallucinations or delusions
Psychomotor disturbance - vary from hypo to hyper, rapid shifts
Sleep-Wake Cycle disturbances - insomnia in night, sleep during the day
Emotional disturbances - anxiety, irritability, can shift rapidly

Question 7

What tools can be used to diagnose someone with delirium?

Answer 7

1. short-Confusion Assessment Method
2. DSM-5 - Diagnostic and Statistical Manual of Mental Disorders.
3. 4A’s Test - alertness, AMT (age, DOB, place, year), attention, acute changes

Question 8

What investigations should be done on a person with delirium? (Confusion screen)

Answer 8

Urinalysis or MSUS - infection or hyperglycemia
Sputum culture
FBC - anaemia
Folate and B12 -
Urea and Electrolytes - AKI or electrolyte disturbances
HbA1c - hyperglycemia
Calcium
LFTs - hepatic failure/encephalopathy
Inflammatory markers - infection/inflammation
Drug levels - digoxin, lithium or alcohol
Thyroid FT - hyper or hypo
CXR - pneumonia or heart failure
Electrocardiogram
CT head - bleed or stroke
Coagulation

Question 9

What are the potention causes of delirium?
Good pneumonic to remember this

Answer 9

CHIMPS PHONED
Constipation
Hypoxia
Infection
Metabolic disturbance
Pain
Sleeplessness
Prescriptions
Hypothermia/pyrexia
Organ dysfunction (hepatic or renal)
Nutrition
Environmental changes
Drugs (over the counter, illicit, alcohol and smoking)

Question 10

What is the appropriate management for delirium?

Answer 10

Identify and treat the underlying cause
Supportive management includes - consistent care team, provide all necessary aids (glasses, hearing, walker)
Environmental adaptation - clock to help with time, family objects, noise levels, lighting and family visits
If medications required use: Haloperidol 0.5mg (anti-psychotic) or Lorazepam 0.5mg (reduce agitation)

Question 11

What should the patient/family be informed of after an episode of delirium in the hospital?

Answer 11

Delirium may continue for a period of time after the cause has been treated
Patient should not drive until delirium has resolved.
Should be given support to manage at home if discharged
Follow-up appointments are advisable.

Question 12

What medications can be given to help with delirium?

Answer 12

Under the advice of a specialist
Haloperidol 0.5mg (anti-psychotic) - competitive antagonist of D2 receptors in brain
Lorazepam 0.5mg (reduce agitation) - GABA agonist.

Question 13

What make up the different exams/investigations for a delirium patient?

Answer 13

History from patients +/or NOK - signs of infection, CHIMPS PHONED - systems review, social history
A to E examination
Cognitive assessment - 4A test