Delirium

Epidemiology

Average age 75years
Average duration 7 days
5% last >4 weeks

Complications

2x increase in discharge mortality
Increase LOS 8 days
Worse recovery at 6 and 12 months
Increased time in residential care

Aetiology

Pre-disposing factors

Dementia

2.5x

Increased age
Cerebral damage
Polypharmacy
Sensory impairment

Hearing 2.6x
Vision 3.8x
Both 12.6x

Residential care
Previous delirium
Alcohol or drug use
Malnutrition

Precipitating Factors

Acute illness
Infections
Drugs
Metabolic abnormalities
Surgery and anaesthesia
IDC
Malnutrition
Change of environment
Sleep deprivation

Drugs

Medications account for >40% of cases of delirium
High risk if started on >3drugs during admission
Anticholinergics
Analgesics
Anti-emetics - scopolamine
Antibiotics – fluroquinolones
CNS acting

Sedatives, anticonvulsants, anti-parkinson

Cardiac

Anti-arrhythmic, digoxin, anti-HTN (B-blocker)

Anti-spasmodics, H@ blockers

Psychotropics – tricyclics, Lithium
Other

Skeletal muscle relaxants, steroids.

Pathophysiology

Cortical and subcortical involvement
Affects

Prefrontal area
Right parietal area
Subcortical structures – Right thalamus and caudate

Theories

Neurotransmitter alterations

Reduced Ach is considered final common pathway

Cortisol
Cerebral hypoxia
Alteration in BBB permeability
Vitamin deficiencies

Clinical Features

DSM IV

Disturbed consciousness
Change in cognition or development of perceptual disturbance
Rapid onset (hours to days), fluctuates during course of the day
Evidence that is result of illness

Types of Delerium

Hyper-alert

Restless, excitable, autonomic hyperactivity

Hypo-alert

Quiet, motionless, drift off to sleep, speech slow
Sicker, longer LOS

Other Symptoms

Delusions
Disturbed sleep-wake cycle
Disturbance of perception

Diagnosis

Cognitive testing

May help identify patients

Confusion assessment method - AIDA

Acute onset
Inattention
Disorganized thinking
Altered level of consciousness (Hyper-vigilant or lethargic)

Shortened MMSE

Orientation questions
3 object recall and WORLD.

Inattention

Digit span
WORLD backwards
Count back from 20
Trail making
Months backwards
Repetition

DDX

Depression
Dementia

Investigations

Potentially useful investigations:

ECG

CXR

ABG

Urine

- MCS

- Drug screen

CT-Brain

Bloods

Electrolytes – Na, Ca, Mg, Po4
TFTs
BSL
Thiamine, B12, Folate, Niacin
LFTs
Coags
FBC, CRP
Osmolality
Drug screen

Optional

LP
EEG
MRI-B

Treatment

Yale delirium Prevention Trial

Intervention group got a combination of non-pharmacological inteventions
Significant decrease in incident delirium

Early discharge to home environment with supports may decrease delirium

Non-Pharmacological

Patient orientated

Orientation
Family visits
Interpreters
Discourage day-time sleeping
Manage constipation

External factors

Reduce restraints
Reduce invasive equipment – IVC, IDC

Environment

Lighting
Single room
Quiet environment
Provision of clock
Avoid room change

Pharmacology

Principals

Aim to use one drug
Aim to use smallest dose
Escalate slowly
Generally try to avoid benzodiazepines as they can worsen delirium

Medications

Haloperidol 0.5mg every daily or BD PO

IM as second line
Max 4mg/24hours

Quetiapine if EPS side effects likely to be a problem

12.5mg PO (rpt in 4hours if needed)
Maximum 50mg over 24hours

Risperidone 0.25-0.5mg daily or BD

Increase to 1-2mg BD
IM olanzapine another option

Benzodiazepines – only if prominent ongoing agitation

Lorazepam 0.5-1mg Q4H to 3mg daily
Oxazepam
IM Midazolam 1mg then small does IV

• 11-40/100,000 per year

• 1/60 persons in a lifetime

• Associated with presence of HSV 1 but causal link not proven

Clinical

Core features:

• Unilateral lower motor facialweakness

• Acute, but not sudden, onset

• Maximal weakness within 72 hours (often within 48hrs)

• Recovery begins within 4 weeks

Other features:

• Pain behind the ear ~50%

o Mild-moderate severity

o Before weakness 25%, contemporaneous 50%, after 25%)

• Taste sensation altered/lost unilaterally 35%

• May be hyperacusis (abnormally acute hearing) ~5%

• Dry eye (Parasympathetic lacrimal involvement) 30%

• Dry mouth (Parasympathetic salivary) 20%

Red flags for alternative diagnosis:

• Other cranial neuropathies (including hearing/vestibular)

• Severe pain

• History of cancer

• Fever

• Rash around ear (Ramsay hunt)

• Gradual progression over time

• Lack of any recovery

Prognosis

• 80% recover with a couple of weeks-months

o Clinical trial 23% incomplete recovery in steroids group vs 32% in controls

• Presence of incomplete paralysis in first week is the best prognostic sign

• Complications:

o Synkinesis

- Motor

- Autonomic (tears when hungry)

Diagnosis:

Typical presentation
No risk factors or symptoms for other causes
Absence of cutaneous lesions of herpes zoster in ear canal
Normal neurological examination except for facial nerve

Investigations:

MRI – may reveal swelling of geniculate ganglion and facial nerve, and maybe entrapment of swollen nerve in temporal bone
EMG may be of some prognostic value

· May be mild CSF lymphocytosis

DDx:

Tumours that invade the temporal bone
Ramsay Hunt Syndrome
Acoustic neuroma
GBS
Sarcoid
Lyme disease

Treatment:

Tape eyelids shut at night to prevent corneal drying
Massage of the weakened muscles
Glucocorticoids 60-80mg during the first 5 days and tapered over the next 5 days
Acyclovir within first 3 days for 10 days may improve outcome.
See trials below – combination may be slightly better than steroids alone
Use of antiviral alone is not effective.

References

Lancet Neurology 2008 7:933

· Prednisone for 10days resulted in faster recovery

· Valaciclovir for 7days did not.

JAMA Meta-analysis

JAMA. 2009;302(9):985-993

· Steroids alone RR 0.69 (of poor outcome), NNT 11

· Anti-viral alone no effect

· Combination RR0.48 – i.e. better than either alone.

Ramsay Hunt Syndrome

· Herpes Zoster oticus

· Triad of

1. Facial paralysis

2. Ear pain

3. Vesicles in auditory canal +/- auricle

· Can also affect cranial nerves V, IX and X

· Vestibular disturbances common

· Worse prognosis for recovery than standard Bell’s palsy

· Antivirals prescribed however data is lacking

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