[8] Delirium Flashcards
What is delirium?
Delirium is an acute, transient, global organic disorder of CNS functioning, resulting in impaired conciousness and attention
What are the different type of delirium?
- Hypoactive
- Hyperactive
- Mixed
What causes delirium?
Delirium has a number of causes, however most cases are multifactorial
What are the categoies of causes of delirium?
- Hypoxic
- Endocrine
- Infection
- Stroke and other intracranial events
- Nutritional
- Post-operative
- Metabolic
- Abdominal
- Alcohol
- Drugs
- Others
What are the hypoxic causes of delirium?
- Respiratory failure
- Myocardial infarction
- Cardiac failure
- Pulmonary embolism
What are the endocrine causes of delirium?
- Hyperthyroidism
- Hypothyroidism
- Hyperglycaemia
- Hypoglycaemia
- Cushing’s
What are the infectious causes of delirium?
- Pneumonia
- UTI
- Encephalitis
- Meningitis
What are the intracranial causes of delirium?
- Stroke
- Raised ICP
- Intracranial haemorrhage
- Space-occupying lesions
- Head trauma
- Epilepsy
- Intracranial infection
What are the nutritional causes of delirium?
- Thiamine deficiency
- Nicotinic acid deficiency
- Vitamin B12 deficiency
What are the post-operative causes of delirium?
- Anaesthetic
- Opiate analgesics
- Post-operative complications
What are the metabolic causes of delirium?
- Electrolyte disturbance
- Hepatic impairment
- Renal impairment
What are the abdominal causes of delirium?
- Faecal impaction
- Malnutrition
- Urinary retention
- Bladder catheterisation
What are the alcohol-related causes of delirium?
- Intoxication
- Withdrawal
What drugs can cause delirium?
- Benzodiazepines
- Opiods
- Anticholinergic
- Anti-Parkinsonian medications
- Steroids
What are the other causes of delirium?
- Severe pain
- Sensory deprivation, for example leaving the person with spectacles or hearing aids
- Relocation
- Sleep deprivation
What are the risk factors for delirium?
- Hospital admission (delirium occurs in 15-20% of general admissions to hospital)
- Older age (65 or over)
- Multiple co-morbidities
- Dementia (2/3 of cases occur in inpatients with pre-existing dementia)
- Physical frailty
- Renal impairment
- Male sex
- Sensory impairment
- Previous episodes
- Recent surgery
- Severe illness
Describe the course of delirium?
Delirium has an acute onset, and takes a fluctating course, often worse at night
What are the symptoms of delirium?
- Disorganised thinking, e.g. slowed, irrational, or incoherent thoughts
- Euphoric, fearful, depressed, or angry
- Language impaired, e.g. rambling speech, repetitive, disruptive
- Illusions, delusions, and hallucinations
- Reveral of sleep-wake pattern
- Inattention
- Unaware/disorientated
- Memory deficits
What is the common form of delirium?
Hyperactive
What is the problem with diagnosis of hyperactive delirium?
It often goes unrecognised, and can be confused with depression
What are the symptoms of hypoactive delirium?
- Lethargy
- Decreased motor activity
- Apathy
- Sleepiness
What are the symptoms of hyperactive delirium?
- Agitation
- Irritability
- Restlessness
- Aggression
- Hallucinations and delusions may be present
What might hyperactive delirium be confused with?
Functional psychoses
What is the ICD-10 criteria for delirium?
- Impairment of consciousness and attention
- Global disturbance in cognition
- Psychomotor disturbance
- Disturbance of sleep-wake cycle
- Emotional disturbances
What is the difference between delirium and dementia in terms of the sleep-wake cycle?
It is disrupted in delirium, and usually normal in dementia
What is the difference between delirium and dementia in terms of attention?
In delirium, it is markedly reduced. In dementia, is is normal or reduced
What is the difference between delirium and dementia in terms of arousal?
It is increased or decreased in delirium, but usually normal in dementia
What is the difference between delirium and dementia in terms of autonomic features
They are abnormal in delirium, normal in dementia
What is the difference between delirium and dementia in terms of duration?
Hours to weeks in delirium, months to years in dementia
What is the difference between delirium and dementia in terms of delusions?
Fleeting in delirium, complex in dementia
What is the difference between delirium and dementia in terms of the course?
It is fluctating in delirium, stable/slowly progressive in dementia
What is the difference between delirium and dementia in terms of the conscious level?
It is impaired in delirium, no impairment in dementia
What is the difference between delirium and dementia in terms of hallucinations?
They are common in delirium, and usually visual. They are uncommon in dementia
What is the difference between delirium and dementia in terms of onset?
Acute/subacute in delirium, chronic in dementia
What is the difference between delirium and dementia in terms of psychomotor activity?
Usually abnormal in delirium, usually normal in dementia
How is delirium investigated?
- Thorough physical investigation
- History
- MSE
- Routine investigations
- Investigations based on history/examination
- Diagnostic questionnaire
What is included in the physical exmaination in delirium?
- ABC assessment
- Conscious assessment (AVPU or GCS)
- Vital signs, including oxygen saturations, pulse, blood pressure, temperature, and capillary blood glucose
- Nutritional and hydration status
- Cardiovascular examination
- Respiratory examination
- Abdominal examination
- Neurological examination
What routine investigations are done in delirium?
- Urinalysis
- Bloods – FBC, U&Es, glucose, CRP, TFTs, B12, folate, ferritin
- ECG – looking for cardiac abnormalities or ACS
- CXR – looking for chest infection
- Infection screen
- Blood culture – sepsis
- Urine culture – UTI
What investigations might be done in delirium, based on history/examination?
- ABG if suspect hypoxia
- CT head if suspect head injury, intracranial bleed, CVA
- Lumbar puncture if suspect meningitis
- EEG if suspect epilepsy
How are diagnostic questionnaires useful in delirium?
They can help with diagnosis and monitoring
What diagnostic questionnaires can be used in delirium?
- Abbreviated mental state test (AMT)
- Confusion assessment method (CAM)
- MMSE
What are the differential diagnoses of delirium?
- Dementia
- Mood disorders – depression or mania
- Late onset schizophrenia
- Dissociative disorders
- Hypothyroidism and hyperthyroidism
How is delirium managed?
- Treat underlying cause
- Reassurance and re-orientation – reassurance will reduce anxiety and disorientation, and patient should be reminded of the time, place, day, and date regularly to re-orientate
- Provide appropriate environment
- Managing disturbed, violent, or distressed behaviour
What are the features of an appropriate environment in delirium?
- Quiet, well-lit side room
- Consistency in care and staff
- Reassuring nursing staff
- Encourage presence of friend or family member
- Optimise sensory acuity
How should disturbed, violent, or distressed behaviour in delirium managed?
- Encourage oral intake and pay attention to continence
- Verbal and non-verbal de-escalation techniques
- Oral low-dose haloperidol (0.5-4mg) or olanzapine (2.5-10mg)
- Avoid benzodiazepines, unless delirium is due to alcohol withdrawal
