Delirium (acute confusional state)

Consciousness:

• Impaired, with onset over hours or days

Can be described as either:

• A mild impairment of thinking, attending, perceiving and remembering
• A mild global impairment of cognitive processes associated with a reduced awareness of the environment

Conscious level fluctuates throughout the day with confusion typically worsening in the late afternoon and at night

Disorientation:

• Disorientation in time (does not know the time, day or year) and place (often more marked) is the rule

Behaviour:

Either:

• Inactivity
• Quietness
• Reduced speech

Or:

• Hyperactivity
• Noisiness
• Irritability (these patients can be very disruptive)

Thinking:

Slow and muddled

Commonly with ideas or delusions (e.g. accusing staff of plotting against them)

Perception:

• Disturbed

Often with illusions and hallucinations (especially visual but also auditory and tactile)

Mood:

• Lability
• Anxiety
• Perplexion
• Fear
• Agitation
• Depression

Memory:

• Impaired during delirium and on recovery
• Amnesia is usual

Differential diagnosis:

• If agitated, consider anxiety
• If delusions or hallucinations, consider primary mental illness (e.g. schizophrenia)
• Remember that in hospitalized ill patients with no psychiatric history, mental illness is rare and delirium is common

Causes:

• Systemic infection (e.g. pneumonia, UTI)
• Drugs (e.g. opiates, anticonvulsants, recreational)
• Alcohol/drug withdrawal
• Metabolic (e.g. hypoglycaemia, uraemia)
• Hypoxia (respiratory or cardiac failure)
• Vascular (CVA, MI)
• Intracranial infection (e.g. encephalitis, meningitis)
• Raised ICP/space-occupying lesions
• Epilepsy (status epilepticus, post-ictal states)
• Head injury (especially subdural haematoma)
• Nutritional (e.g. thiamine, B₁₂ deficiency)

Management:

1. Identify and treat the underlying cause
2. Reduce distress and prevent accidents
3. Nurse in a moderately lit, quiet room with the same staff in attendance (minimizes confusion) where the patient can be watched closely
4. Minimize medication (especially if sedative)

If the patient becomes agitated and disruptive, some sedation may be necessary:

Use a major tranquilizer (e.g. haloperidol 0.5-2mg IM/PO)

Wait 20 mins to judge effect as further doses can be given if needed