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Information ⬇

Author: David Sprigings

Consider delirium (Box 4.1) in patients with:

Several neuropsychiatric disorders may give rise to abnormal consciousness, language, memory or behaviour, and should be considered in the differential diagnosis of delirium (Table 4.1).

Causes of delirium are given in Appendix , and diagnoses to consider in specific patient groups in Table 4.2. Assessment of the patient with delirium is summarized in Figure 4.1.

Priorities ⬆ ⬇

  1. Make a rapid assessment to ensure that airway, breathing and circulation are not compromised. Check blood glucose and correct hypoglycaemia (Chapter 81).
  2. Assess the mental state. This can be done using the ten-item abbreviated mental test score (Table 4.3) or equivalent.
    • The diagnosis of delirium is based on the criteria shown in Table 4.1. Delirium is characterized by a change in the mental state (occurring over hours or days, often fluctuating over the course of the day), associated with a causative acute medical or toxic illness (Appendix ).
    • The duration of the patient's abnormal mental state, as assessed by a reliable witness, often helps distinguish delirium from dementia (which may of course coexist).
  3. What is causing delirium?
    • Establish current symptoms, context and past history by talking to family members, carers or hospital staff, and reviewing relevant medical records.
    • Check the drug chart. Many drugs may cause delirium, notably benzodiazepines, tricyclics, analgesics (including NSAIDs), lithium, corticosteroids, and medications for parkinsonism.
    • If the patient was admitted with delirium, find out exactly what drugs were being taken prior to admission: if necessary, contact the patient's general practitioner to check which drugs were prescribed, and ask relatives to collect all medications in the home.
    • Review the physiological observations and make a systematic examination. Check for focal chest signs, abdominal tenderness or guarding, urinary retention, faecal impaction, pressure ulceration and cellulitis. Are there abnormal neurological signs? As a minimum, examine for neck stiffness and lateralized weakness, and check the plantar responses.
    • Consider non-convulsive status epilepticus if there are mild clonic movements of the eyelids, face or hands, or simple automatisms. Diazepam (10 mg IV, at a rate of <2.5 mg/min) may terminate the status with improvement in conscious level. Seek advice from a neurologist.
    • Are there signs suggesting liver failure (jaundice, asterixis, ascites, signs of chronic liver disease)? See Chapter 77 for further management of acute liver failure and decompensated chronic liver disease.
    • In patients with delirium in the context of alcohol-use disorder, check for other signs of Wernicke's encephalopathy: nystagmus, VI nerve palsy (unable to abduct the eye) and ataxia (wide-based gait; may be unable to stand or walk). See Chapter 106 for management.
    • Test a urine specimen if available for white cells, blood and protein. If there is fever or low temperature, new focal chest signs or oxygen saturation is <94% breathing air, arrange a chest X-ray. Other investigations needed are given in Table 4.4.
  4. Neuroimaging (by CT or MRI) is indicated if:
    • Delirium followed a fall or head injury.
    • A primary neurological disorder (e.g. encephalitis) is suspected.
    • There are new focal neurological signs.
    • There is papilloedema or other evidence of raised intracranial pressure.
    • The patient has cancer, HIV-AIDS or other cause of immunosuppression.
    • The patient's behaviour prevents adequate neurological examination.
    • No systemic cause for the delirium is apparent.
  5. Lumbar puncture with examination of the cerebrospinal fluid should be done (assuming no contraindication to lumbar puncture) if:
    • Meningitis (Chapter 68) or encephalitis (Chapter 69) is suspected.
    • The patient is febrile and no systemic focus of infection is found.
    • The cause of delirium remains unclear.
  6. Electroencephalography(EEG) is indicated if:
    • Non-convulsive status epilepticus or encephalitis is suspected.
    • It is unclear if the diagnosis is delirium or psychosis.
    • No cause for delirium is apparent, despite investigation.

Further Management ⬆ ⬇

  • Identify and treat the underlying cause (Appendix ; Table 4.2).
  • Ensure comprehensive supportive care (Table 4.5), with avoidance of physical restraint, and anticipation and prevention of complications of delirium (e.g. dehydration, constipation, pressure ulceration).
  • Review the drug chart. Avoid unnecessary medications, especially those with an anticholinergic effect.
  • If needed, to relieve severe distress or prevent injury, give short-term therapy (one week or less) with haloperidol (in a dose of <3 mg daily) or olanzapine (the latter is contraindicated in patients with dementia).

Further Reading ⬆

Fong TG, Davis D, Growdon ME, Albuqerque A, Inouye SK. (2015) The interface between delirium and dementia in elderly adults. Lancet Neurol 14, 823–832.

Inouye SK, Westendorp RGJ, Saczynski JS. (2013) Delirium in elderly people. Lancet 383, 911–922.

National Institute for Health and Care Excellence (2010) Delirium: prevention, diagnosis and management. Clinical guideline (CG103) Reviewed January 2015. https://www.nice.org.uk/guidance/cg103?unlid = 9628712972016102061852

Woodford HJ, George J, Jackson M. (2015) Non-convulsive status epilepticus: a practical approach to diagnosis in confused older people. Postgrad Med J 91, 655–661.