13.01.08 Delirium

Definition

• 1. Disturbed consciousness

  2. Change in cognition

  3. Acute onset and fluctuating course

  4. Cause by a medical condition or treatment

Urgency

• • Many LIFE-THREATENING conditions can cause delirium

    • => Assess as a priority

    • Especially if young, healthy

  • May need to aggressively treat the underlying cause

Pathogenesis

• • 1. Medications

    • Sedatives

    • Steroids

      • Steroid psychosis : If high dose for a long time

    • Opioids

    • Antihistamines

      • Incl. OTC

    • Digoxin

    • Lithium

  • 2. Infection

  • 3. Metabolic

    • Electrolytes

      • Hypercalcaemia

        • Cancer

        • Unlikely to be from hyperparathyroidism (slower rise => adaptation)

      • Hyponatraemia

      • Hypernatraemia

      • Hypophosphataemia

        • Refeeding syndrome

        • Brain can't make enough ATP

      • Hypomagnesiumaemia

        • cf Use is fitting (opposite effect)

    • Endocrine

      • Diabetes

        • Hypoglycaemia, HHS, DKA

      • Thyroid storm

      • Hypothyroidism

      • Cushing's

      • Addison's

  • 4. Failure

    • Heart, resp, renal, liver

  • 5. CNS

    • Meningitis

      • Beware atypical presentations in the elderly

        • e.g. Temp. may be low as well as high

      • Listeria is common is elderly (as well as infants)

        • From out of date dairy products (can't read the label)

    • SDH, psychiatric condition, transient global amnesia (TGA), epilepsy, hypertensive encephalopathy

  • 6. Physical

    • Dehydration

    • Pain

      • Don't forget to give decent pain relief for hip fractures!

    • Catheters

      • Use condom catheter or pads

    • Lines

    • Hypo/hyperthermia

Differentials

• • Dementia

  • Stroke

    • Frontal lobe

    • Wernicke's

      • Verbal diarrhoea

    • Occipital

      • Cortical blindness => Seeing snakes

  • Non-convulsive status epilepticus

  • Primary psychiatric illness

    • Psychosis

    • Depression

    • Bipolar

    • Schizophrenia

Confusion Assessment Method (CAM)

• • Feature 1: Acute Onset and Fluctuating Course

    • Is there evidence of an acute change in mental status from the patient’s baseline?

    • Did the (abnormal) behavior fluctuate during the day, that is, tend to come and go, or increase and decrease in severity?

  • Feature 2: Inattention

    • Did the patient have difficulty focusing attention, for example, being easily distractible, or having difficulty keeping track of what was being said?

  • Feature 3: Disorganized thinking

    • Was the patient’s thinking disorganized or incoherent, such as rambling or irrelevant conversation, unclear or illogical flow of ideas, or unpredictable switching from subject to subject?

  • Feature 4: Altered Level of consciousness

    • This feature is shown by any answer other than “alert” to the following question:

      • Overall, how would you rate this patient’s level of consciousness? (alert [normal]), vigilant [hyperalert], lethargic [drowsy, easily aroused], stupor [difficult to arouse], or coma [unarousable])

  • The diagnosis of delirium by CAM requires the presence of features 1 and 2 and either 3 or 4

IQ code

• • For collateral history

  • Compare with the patient 10 years ago

Management

• • INVOLVE PHYSIOS EARLY

  • Avoid

    • Precipitating factors

  • Treat

    • Underlying cause

  • Support

    • Aspiration, hydration, nutrition, mobility, skin + pressure care, incontinance

  • Control

    • Behaviour

Medication

• • Haloperidol

    • 1st choice

  • Lorazepam

    • Short half life

  • Quetiapine

    • If pre-existing dementia

  • NOT risperidone/olanzapine

    • Stroke risk

Prevention

• • Orientation protocols

    • Mandatory on psych wards

  • Cognitive stimulation

  • Keep on general ward

    • Beware of over- and under- stimulation

  • Don't move at night

  • Early mobilisation

  • Minimise restraint

  • Adequate hydration

Notes

• • ACS vs Delirium

    • ACS is hypoactive

    • Delirium is hyperactive

  • Aim for <6 drugs in elderly care

  • Differentials co-exist in 50% of cases

  • Focal neurology or trauma => Immediate CT head

  • Delirium => 2x mortality

  • The key intervention is PHYSIOTHERAPY