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.
- Onset usually over hours/days.
- Attention / consciousness
- Cognitive function
- Perception
Describe hyperactive delirium.
- Causes the patient to experience:
- Agitation
- Restlessness
- Aggression
- Loss of concentration
- Confusion
- May have hallucinations / delusions
- Can be difficult to manage
- Agitation
- Restlessness
- Aggression
- Loss of concentration
- Confusion
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.
- Slowing down
- Sleepiness/lethargy
- Reduction of consciousness
- Reduced speech or interaction
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.
- Arousal
- Sleep
- Pain
- Muscle tone
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.
Describe the confusion assessment method (CAM).
Consider the diagnosis of delirium and if 1 and 2, AND either 3a or 3b is present:
- Acute onset? Yes / no
- Inattention? Yes / no
- (a) Disorganised? (b) Altered consciousness? Yes / no
Describe the 4AT.
- Alertness
- Normal = 0
- Mild sleepiness for <10 seconds on waking = 0
- Clearly abnormal = 4
- AMT 4
- Age, DOB, place, current year?
- No mistakes = 0
- 1 mistake = 1
- ≥2 mistakes = 2
- Attention
- Ask patient to recite the months of the year backwards starting at December.
- Achieves ≥7 correctly = 0
- Starts but scores <7 months / refuses to start = 1
- Untestable (cannot start because too unwell, drowsy, inattentive) = 2
- Acute change
- Evidence of significant change or fluctuation in:
- Alertness
- Cognition
- Other mental function (hallucinations, paranoia) arising over the last 2 weeks and still evident in the last 24 hours.
- No = 0
- Yes = 4
- Normal = 0
- Mild sleepiness for <10 seconds on waking = 0
- Clearly abnormal = 4
- Age, DOB, place, current year?
- No mistakes = 0
- 1 mistake = 1
- ≥2 mistakes = 2
- Ask patient to recite the months of the year backwards starting at December.
- Achieves ≥7 correctly = 0
- Starts but scores <7 months / refuses to start = 1
- Untestable (cannot start because too unwell, drowsy, inattentive) = 2
- Evidence of significant change or fluctuation in:
- Alertness
- Cognition
- Other mental function (hallucinations, paranoia) arising over the last 2 weeks and still evident in the last 24 hours.
- No = 0
- Yes = 4
Describe the scoring of the 4AT.
- Total between 0 and 12
- ≥4 = possible delirium
- 1-3 = possible cognitive impairment
- 0 = delirium or significant cognitive impairment unlikely
What are the precipitating causes of delirium?
-
Intracranial - infarction / bleed / infection / post-ictal / medications.
-
Extracranial - infection, metabolic, hypoxia, stress response, anaesthesia and surgery, any severe illness, pain.
-
Environmental / iatrogenic - emotional distress, sleep deprivation, change in environment, sensory impairment, catheters, drips, urinary retention, constipation.
What is the delirium time bundle?
-
Think, exclude and treat possible triggers.
-
Investigate and intervene to correct underlying causes.
-
Management plan.
-
Engage and explore
Describe the 'T' in the delirium time bundle.
- Think, exclude and treat possible triggers.
- NEWS/FEWS - think of the sepsis 6.
- Blood glucose.
- Medication history.
- Pain review (Abbey pain scale).
- Assess for urinary retention.
- Assess for constipation.
List the possible trigger medications for a delirium (starting or stopping).
- Opiates (morphine, codeine, tramadol)
- Anticholinergics (e.g. for bladder symptoms, pain killers)
- Benzodiazepines (diazepam, nitrazepam)
- Drugs used in Parkinsons
- Antipsychotics
- Antiepileptics
- Antihistamines
- Antihypertensives (if BP is too low or for low Na2+
Describe the 'I' in the delirium time bundle.
- Investigate and intervene to correct the underlying cause.
- Assess hydration and start fluid balance chart.
- Blood (FBC, U&E, CRP, Ca, LFT, Mg, glucose).
- Look for symptoms/signs of infection (skin, chest, urine, CNS) and perform appropriate cultures and imagine depending on clinical assessment.
- ECG - because acute coronary syndrome can cause delirium.
Describe the 'M' in the delirium time bundle.
- Management plan
- Initiate treatment of all underlying causes found above.
Describe the 'E' in the delirium time bundle.
- Engage and explore
- Engage with patient / family / carers - explore if this is unusual behaviour.
- Explain diagnosis of delirium to the patient, family and carers (use delirium leaflet).
- Document diagnosis of delirium.
In some cases, urgent neuro-imaging will be required. What are the circumstances?
- If the patient is anti-coagulated.
- History of fall with head injury.
- New focal neurological signs.
Describe the treatment of delirium.
- Identify and treat the underlying cause.
- Reduce or remove culprit medications.
- Maintain hydration and nutrition.
- Reorientation strategies.
- Maintain mobility.
- Normalise sleep wake cycle.
- Pharmacological management.
Prevention is better than cure!
Describe the non-pharmacological management options for deliruim.
- Re-orientation strategies and distraction.
- Involve families / familiar people.
- Use glasses / hearning aids.
- Keep mobile and avoid restraints.
- Promote sleep with a quiet room at night, bright light during the day and dim at night, avoid day time napping.
Describe the appropriate communication strategies for dealing with a delirium patient.
- Introduce yourself and explain who you are, what you are doing and where you are - may need to repeat.
- Useful to explain delirium.
- Smile, make eye contact and be friendly.
- Don't argue about delusions, try to persuade but if not possible use distractions.
- Get help from familiar faces (family, carers).
- Remember the patient may be aggressive because they are scared.
Describe the boundaries of pharmacological treatment of delirium.
