Recognising and Managing Acute Confusional State Flashcards
What is delirium?
- An episode of acute confusion.
- Onset usually over hours/days.
- Delirium is a clinical syndrome which has disturbed:
- Attention / consciousness
- Cognitive function
- Perception
- Fluctuates
- Due to underlying causes.
- Can be hyperactive or hypoactive.
Describe hyperactive delirium.
- Causes the patient to experience:
- Agitation
- Restlessness
- Aggression
- Loss of concentration
- Confusion
- May have hallucinations / delusions
- Can be difficult to manage
Describe hypoactive delirium.
- Hypoactive delirium causes:
- Slowing down
- Sleepiness/lethargy
- Reduction of consciousness
- Reduced speech or interaction
- Higher mortality / poor prognosis
- Much harder to spot - is often just thought to be lathargia or illness.
Describe mixed delirium.
A fluctuation between hyperactive and hypoactive delirium. A patient can swing from one to the other several times per day.
Compare and contrast delirium and dementia.
Delirium
Dementia
Sudden onset
Gradual onset
Fluctuates
Does not usually fluctuate
Consciousness: attention reduced
Consciousness: unchanged
Perception: hallucinations common
Perception: hallucinations usually a late feature
Speech: can be incoherent / slow / rapid
Speech: repetitive
Usually reversible
Usually not reversible
Which patients are likely to develop delirium?
- Anyone with a severe enough insult (regardless of age).
- Very common in ITU.
- Vulnerable and frail people develop delirium with a much smaller insult - less physiological reserve.
- Common in people with dementia - if a sudden worsening, screen for an underlying cause.
What are the risk factors for delirium?
- Age >65
- Background cognitive impairment or dementia.
- Surgery, especially hip fracture - most people who have surgery for hip fracture are older and frail so it is probably the demographic which makes delirium more probable than the surgery itself.
- Comorbidities.
- Polypharmacy - 4+ medications increases risk.
- Sensory impairment.
- Functional Impairment - problems walking, needing help to go to the toilet.
- Sleep disturbance.
- Hospital admission.
Describe the main changes in the body associated with ageing.
- Brain volume decreases by 5% per decade after 40.
- Vascular changes - up to 20% less blood flow.
- Reduced neurotransmitters (dopamine reduces by 10% per decade in adulthood).
- Kidney and liver function - unable to clear drugs.
- Decreased muscle mass, total body water and increased body fat - this changes how drugs are distributed through the body and this could potentially cause delirium.
Describe frailty.
- Health state related to the ageing process in which multiple body systems gradually lose their in-built biological reserves.
- People lose their ability to compensate when they are medically challenged.
- Minor illnesses / insults can cause delirium and falls.
What are the effects of delirium? Why is it important?
- Increased length of stay in hospital (21 vs. 9 days).
- Increased risk of dying - in hospital (11% vs. 6%) and up to 1 year later (27% vs. 15%).
- Increased risk of dementia.
- Increased risk of falls, pressure sores.
- More likely to go into 24 hour care (47% vs. 18% at 1 month).
- Can be very frightening for patient and family.
- Risk of death rises rapidly if not identified - increases by 11% with every 48 hour delay in diagnosis.
- If identified adn communicated appropriately can be followed-up and screened for dementia.
Describe the pathophysiology of delirium.
- Mechanisms are not fully understood - hypothesis based on animal models.
- Changes to blood-brain barrier permeability; things which normally stay in peripheral circulation can enter the brain.
- Cerebral hemispheres or arousal mechanisms of the thalamus and brain stem reticular formation become impaired.
Describe the pathophysiological mechanism of delirium.
- Increased cortisol / stress
- Increased cytokines (TNFα, IL1) / inflammation
- Increased dopamine
- Increased serotonin - stimulates the cortex.
- Increased GABA
- Decreased acetylcholine transmission (extremely important in cognition)
What is the function of the reticular activating system?
- Network in the brain stem.
- Responsible for:
- Arousal
- Sleep
- Pain
- Muscle tone
- Ascending fibres arouse and activate the cerebral cortex.
- Controls levels of consciousness.
Describe the process of identifying delirium.
- Full history - obtain collateral history.
- Key factors are acute onset, fluctuation, decreased attention.
- Review medication.
- Vital signs (NEWS scoring).
- Physical and neurological examination for signs of infection, dehydration, neurological changes.
- Consider capacity.
- Consider in any confused older person and don’t assume they have dementia (collaborative history).
- Look for plucking of bed clothes and air (carphology and floccillation).
- Use a screening tool.
- Up to 50% of cases missed by medical professionals.
What are the screening tools used in the identification of delirium?
- SQiD - fo you think your relative has ben more confused recently?
- CAM - confusion assessment method.
- 4AT - recommended by Scottish Delirium Association.