Delirium

Question 1

MOA of aciclovir

Answer 1

An antiviral (guanine analogue). Guanine analogues inhibit viral DNA polymerase and DNA synthesis.

Question 2

Aciclovir indications

Answer 2

Treatment and prevention of HSV infections, shingles, acute chickenpox.

Question 3

Aciclovir adverse effects

Answer 3

Encephalopathy, hallucinations, headache, injection site reactions, nephrotoxicity

Question 4

MOA of levetiracetam (keppra)

Answer 4

Exact mechanism unknown. May modulate neurotransmission by binding to synaptic vesicle protein 2A.

Question 5

Levetiracetam is only covered by PBS if used:

Answer 5

as a second-line treatment

Question 6

Adverse effects of levetiracetam

Answer 6

Behavioural changes, drowsiness, weakness, vertigo, insomnia

Question 7

Major causes of delirium (MNEMONIC)

Answer 7

I WATCH DEATH

Infection
Withdrawal
Acute metabolic disorder
Trauma
CNS pathology
Hypoxia
Deficiencies
Endocrine
Acute vascular
Toxins/drugs
Heavy metals

Question 8

Drugs/toxins that are associated with delirium include:

Answer 8

Anticholinergics
Benzodiazepines
Antihistamines (in older patients)
Opioids
Recreational drugs
Alcohol use disorder
Heavy metals

Question 9

Metabolic causes of delirium include:

Answer 9

Liver or renal failure
Diabetic ketoacidosis
Hyper/hypothyroidism
Electrolyte abnormalities
Vitamin deficiencies (B12, folic acid, thiamine)

Question 10

Delirium features of onset

Answer 10

Sudden. Prodromal phase may proceed.

Question 11

Delirium time course

Answer 11

Rapid and fluctuating. Hours to days.

Question 12

Delirium level of consciousness

Answer 12

Impaired (fluctuating)

Question 13

Delirium effect on attention

Answer 13

Impaired (fluctuating)

Question 14

Memory changes in delirium

Answer 14

Recent memory loss

Question 15

Delirium effects on thought process

Answer 15

Disorganised

Question 16

Delirium and hallucinations

Answer 16

Present - often visual or tactile.

Question 17

Delirium and psychomotor activity

Answer 17

Psychomotor activity is altered (increased or decreased)

Question 18

Delirium reversibility

Answer 18

Delirium is a reversible condition.

Question 19

Delirium definition

Answer 19

Acute, reversible alteration in the level of awareness and attention.

Question 20

Concerning intracranial features of a patient with delirium

Answer 20

History of trauma
Focal neurological symptoms
Seizure
Fever with headache or meningismus

Question 21

Diagnostic studies for delirium of a suspected intracranial aetiology

Answer 21

Neuroimaging (CT/MRI head)
EEG (shows diffuse slowing of background activity in patients with delirium
Lumbar puncture and CSF analysis

Question 22

Concerning pulmonary features in a patient with delirium

Answer 22

Fever with cough or shortness of breath
Risk factors for aspiration pneumonia

Question 23

Diagnostic studies for delirium of a suspected pulmonary aetiology

Answer 23

CXR

Question 24

Concerning cardiovascular features in a patient with delirium

Answer 24

Abnormal haemodynamics
Chest pain
Worsening peripheral oedema and/or shortness of breath

Question 25

Diagnostic studies for delirium of a suspected cardiovascular aetiology

Answer 25

ECG Echocardiogram

Question 26

Concerning features in a patient with delirium suggestive of a nutritional aetiology include:

Answer 26

Hx of heavy drinking Malabsorptive disorders Malnutrition

Question 27

Diagnostic studies for delirium of a suspected nutritional aetiology

Answer 27

Vit. B12, folate and thiamine levels

Question 28

Concerning features in a patient with delirium suggestive of a toxic aetiology include:

Answer 28

Hx of alcohol or recreational drug use Suspicion of CO poisoning

Question 29

Diagnostic studies for delirium of a suspected toxic aetiology

Answer 29

Consider urine toxicology or serum drug levels

Question 30

Concerning features in a patient with delirium suggestive of an infectious aetiology include:

Answer 30

Fever RFs for blood borne diseases or STIs

Question 31

Diagnostic studies for delirium of a suspected infectious aetiology

Answer 31

Bacterial cultures (urine, blood) Serum lactate HIV, syphilis serology

Question 32

First-line investigations in the diagnosis of delirium include:

Answer 32

CBE Serum glucose Electrolytes Urinalysis

Question 33

The most common causative pathogens in encephalitis are:

Answer 33

1. Herpes simplex virus 2. Varicella zoster virus

Question 34

All patients with suspected encephalitis should undergo the following investigations:

Answer 34

Neuroimaging (MRI brain with contrast) Lumbar puncture with CSF analysis EEG

Question 35

What is the pathognomonic sign of HSV encephalitis?

Answer 35

Bilateral temporal lobe involvement on imaging.

Question 36

CSF analysis in the setting of encephalitis includes:

Answer 36

PCR, gram stain and cultures

Question 37

The gold-standard diagnostic test for HSV encephalitis is:

Answer 37

CSF PCR for HSV-1 and HSV-2 (allows for early detection of pathogen and targeted treatment)

Question 38

CSF findings in HSV encephalitis

Answer 38

Increased lymphocytes (lymphocytic pleocytosis) Normal or increased opening pressure Normal to mildly increased lactate Mild protein elevation Normal glucose

Question 39

Common focal neurological deficits for encephalopathy affecting the medial temporal lobe include:

Answer 39

Altered sense of smell Loss of vision Aphasia Memory loss Hemiparesis Ataxia Hyperreflexia

Question 40

The most common strain of HSV implicated in adult viral encephalitis is:

Answer 40

HSV-1

Question 41

Patients with suspected viral encephalitis should begin empiric therapy immediately with:

Answer 41

aciclovir

Question 42

When administering IV aciclovir patients should be monitored for:

Answer 42

Nephrotoxicity. Manage with adequate hydration and adjust doses for renal function.

Question 43

Prognosis of HSV encephalitis

Answer 43

Fatal in up to 70% of cases if left untreated.

Question 44

Examination features of viral encephalitis

Answer 44

Fever Vesicular rash Focal neurological deficits Meningismus (neck stiffness, Kernig's sign, Brudzinski's sign)

Question 45

Electrolyte disturbances associated with delirium include:

Answer 45

Hypernatraemia Hyponatraemia Hypercalcaemia

Question 46

Anticholinergics mechanism of action

Answer 46

Block the neurotransmitter Ach in the central and peripheral nervous system. Most anticholinergics are muscarinic antagonists which inhibit the effect of Ach on muscarinic receptors.

Question 47

Side effects of anticholinergics

Answer 47

Mydriasis Delirium Flushing Hyperthermia Decreased secretions/dry skin Urinary retention Paralytic ileus Tachycardia MNEMONIC: BLIND as a bat (mydriasis), MAD as a hatter (delirium), RED as a beet (flushing), HOT as a hare (hyperthermia), DRY as a bone (decreased secretions), the bowel and bladder lose their TONE (urinary retention/paralytic ileus) and the heart runs ALONE (tachycardia)

Question 48

The mainstay of delirium treatment is:

Answer 48

Treatment of the underlying condition and supportive care. Consider discontinuing causative medications e.g. anticholinergics. Maintain adequate hydration.

Question 49

Indications for pharmacological management of delirium

Answer 49

Patient is in significant distress or considered to be a threat to themselves/others.

Question 50

The following drugs can be used in the pharmacological management of delirium (as a last resort)

Answer 50

Haloperidol Olanzapine Risperidone