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          • From out of date dairy products (can't read the label)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