Post-op delirium

(formerly post-operative cognitive dysfunction)

 

Definition of delirium:

·        Organic cerebral syndrome

·        Aetiologically non-specific

·        Acute onset and fluctuating course

·        Disturbance in attention, awareness, cognition

·        Can be hyperactive, hypoactive or mixed

 

Contributors:

Pre-existing

·     Old

·     Cognitive impairment

·     Hearing or vision impairment

·     Comorbidities

·     Poor functional status

·     Polypharmacy

General insults

·     Sleep deprivation

·     Malnutrition

·     Urinary retention

·     Constipation

Specific pathology

·     Hypoxaemia

·     Hypothermia

·     Dehydration

·     Electrolyte derangement

·     Infection

·     Renal impairment

Surgery and anaesthesia

·     Long duration

·     Hip fracture

·     Aorta

 

Post-op timeline:

Within 1/52

Post-op delirium

Within 1/12

Post-op neurocognitive disorder

After 1/12

Neurocognitive disorder

*Post-operative cognitive dysfunction is no longer a thing*

 

Intra-op prevention:

General management

·     Cause is surgery + anaesthesia, not anaesthesia alone

·     General and neuraxial are the same

·     Light sedation and deep sedation are the same

·     Blood pressure fluctuation is bad

Anaesthesia drugs

·     BIS <40 is bad

·     Propofol is probably better than the fluranes

·     Dexmedetomidine is good (load 0.5mcg/kg, infuse 0.2mcg/kg/h)

·     Ketamine is good at analgesic infusion rates

·     Benzodiazepines are bad

Other drugs

·     Dexamethasone is good (??)

 

Post-op prevention:

Drugs to give

·     Adequate analgesia

·     Dexmedetomidine infusion if in ICU

Drugs to avoid

·     Beer’s list

·     Multiple new medications

·     Tricyclic antidepressants (central anticholinergic)

·     Glucocorticoids

·     Benzodiazepines

·     Other sedative-hypnotics

 

*Use psychoactives as last resort in managing delirium*

*Start low, go slow*

Medical

·     Prompt diagnosis of complications e.g. UTI

·     Avoid hypovolaemia

·     Avoid electrolyte disturbance

·     Remove urinary catheter early

Nursing and allied health

Multi-disciplinary programme:

·     Regular screening for delirium

·     Orientation

·     Vision and hearing aids

·     Sleep hygiene

·     Early mobilization

·     Cognitive stimulation

 

*reduces cost*

*reduces institutionalization*

 

 

Feedback welcome at ketaminenightmares@gmail.com