Acute confusional state (delirium)

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    Last updated: July 2022


    Clinical features

    The clinical picture includes:

    • disorientation in time and space;
    • impaired consciousness;
    • concentration problems;
    • memory impairment.

    These symptoms develop rapidly (hours or days), and often fluctuate during the course of the day.
    Agitation, delusions, behavioural disorders and hallucinations (often visual) may be associated symptoms.


    Delirium almost always has an organic cause:

    • Infectious: meningitis, severe malaria, encephalitis, septicaemia, syphilis, AIDS, etc.
    • Metabolic: hyper/hypoglycaemia, electrolyte imbalance, niacin (vitamin PP or B3) or thiamine (vitamin B1) deficiencies, etc.
    • Endocrine: thyroid disorders
    • Neurological: epilepsy, raised intracranial pressure, head trauma, meningeal haemorrhage, brain tumour, etc.

    Also consider the use of drugs which may cause delirium (opioid analgesics, psychotropic drugs, fluoroquinolones, etc.), use of toxic substances (alcohol/drugs), or withdrawal from these substances.


    Delirium requires hospitalisation.

    • Treat the underlying cause.
    • Provide supportive care (i.e. nutrition, fluid, electrolyte balance); ensure bladder function.
    • Ensure that the patient receives only medications appropriate to their needs.
    • Treat pain if needed (see Pain, Chapter 1);
    • Ensure adequate sensory environment: low lightening, limit noise.


    The administration of diazepam may increase delirium. If it is absolutely necessary to sedate an agitated patient, use low dose haloperidol for a short time (7 days or less):
    haloperidol PO: 0.5 to 1 mg 2 times daily
    or haloperidol IM: 0.5 to 1 mg, to be repeated if the patient is still agitated 30 to 60 minutes after the first injection.

    If necessary, administer additional doses every 4 hours, do not exceed a total dose of 5 mg daily.


    In case of delirium related to alcohol withdrawal (delirium tremens):

    • Admit the patient to an intensive care unit.
    • Administer diazepam IV: 10 to 20 mg 4 to 6 times daily, under close supervision with ventilation equipment near at hand.
      The goal is to achieve mild sedation without provoking respiratory depression. The doses and duration of the treatment are adjusted according to the clinical progress.
    • IV hydration: 2 to 4 litres 0.9% sodium chloride per 24 hours.
    • Administer thiamine IM or very slow IV (over 30 minutes): 100 mg 3 times daily for 3 to 5 days.
    • Monitor vital signs and blood glucose levels.