Emergence delirium in children: functional explanation and

possible treatments

Andrew Davidson

Royal Children’s Hospital, Melbourne

Outline

• Defining emergence delirium

• Sleep and parasomnias

• A possible mechanism for emergence delirium

• Preventing and managing emergence delirium

What is emergence delirium?

• Preschool child, uneventful volatile anaesthetic, block seemed to be working, left the child unconscious in PACU

• Start to hear the screaming as you collect your next case

• Child awoke suddenly, crying and screaming incoherently, trying to get off trolley, not looking at the nurses, has pulled off dressings and pulled out the IV, inconsolable, being restrained

• Parents arrive but child pushes them away, they say “he’s behaving like he is not my child”

• 20 minutes later child slows down, goes to sleep, awakens quietly 5 minutes later

• Preschool child, uneventful volatile anaesthetic, block seemed to be working, left the child unconscious in PACU

• Start to hear the screaming as you collect your next case

• Child awoke and shortly afterwards is crying and screaming “ouch” “mummy”, looking angrily at nurses, has pulled off dressings and pulled out the IV, briefly consolable, being restrained

• Parents arrive and child reaches for them

• Preschool child, uneventful volatile anaesthetic, block seemed to be working, left the child unconscious in PACU

• Child opens eyes briefly, starts moaning, rolls over repeatedly tangling lines but not dislodged, nurses ask what’s wrong and tell the child to lie still, but only get moaning and incoherent response

• Parents arrive and child does not acknowledge their presence

• After 5-10 minutes child goes back to sleep

How to measure emergence delirium?

Scores used to measure ED

• PAED

• Watcha

• Cravero

• KEDS

Cravero

Watcha

PAED

Delirium

• Reduced awareness of environment - non responsive

• Altered cognition, perceptual disturbance -disoriented

Item Description Yes No

Awake Child has eyes open or is vocalisingScale not

appropriate

Purposeful

Child displays purposeful movement, e.g. reaching for a caregiver, eating, drinking. Agitated behaviours may be purposeful, e.g. kicking and thrashing when forced to take medication

Responsive

Child is responsive to stimuli, interacting with people or objects in his/her environment. May be verbal or non-verbal, e.g. following instructions, responding to questions appropriately, pushing away/drinking from a bottle placed to his/her mouth

Eyes openChild’s eyes are open. If eyes are closed, answer “No” to this item and “N/A” for Stare and Avert gaze.

StareChild is staring blankly, not directing his/her gaze meaningfully

Yes No N/A

Avert gazeChild’s gaze is directed to the right/left, with no obvious object of attention; not directing gaze meaningfully

Yes No N/A

KEDS

Item Yes No

AwakeScale not

appropriate

Purposeful

Responsive

Eyes open

Stare Yes NoN/A

Avert gaze Yes No

X

X

X

XX

XX

X

Agitation Delirium

Crying, screaming

Thrashing, punching

No eye contact

Non responsive

Disoriented

X

Cravero

Agitation

Agitation

Watcha

Agitation

Agitation

Delirium

PAED

Delirium

Agitation

DeliriumDelirium

Delirium

• Preschool child, uneventful volatile anaesthetic, block seemed to be working, left the child unconscious in PACU

• Start to hear the screaming as you collect your next case

• Child awoke suddenly, crying and screaming incoherently, trying to get off trolley, not looking at the nurses, has pulled off dressings and pulled out the IV, inconsolable, being restrained

• Parents arrive but child pushes them away, they say “he’s behaving like he is not my child”

• 20 minutes later child slows down, goes to sleep, awakens quietly 5 minutes later

Delirium with agitation

• Preschool child, uneventful volatile anaesthetic, block seemed to be working, left the child unconscious in PACU

• Start to hear the screaming as you collect your next case

• Child awoke and shortly afterwards is crying and screaming “ouch” “mummy”, looking angrily at nurses, has pulled off dressings and pulled out the IV, briefly consolable, being restrained

• Parents arrive and child reaches for them

Agitation

• Preschool child, uneventful volatile anaesthetic, block seemed to be working, left the child unconscious in PACU

• Child opens eyes briefly, starts moaning, rolls over repeatedly tangling lines but not dislodged, nurses ask what’s wrong and tell the child to lie still, but only get moaning and incoherent response

• Parents arrive and child does not acknowledge their presence

• After 5-10 minutes child goes back to sleep

Delirium

Normal sleep and parasomnias

Normal sleep

Parasomnias

• Occur in children

• Arousal from deep NREM sleep

• Continuum of behaviour without conscious awareness

Confusional arousal – little motor or autonomic features

Somnambulism – complex motor

Sleep terror – fear and autonomic features, variable motor

Night terror

• Children often scream and are very frightened and confused

• They thrash around violently and are often not aware of their surroundings

• May be unable to talk to, comfort, or fully wake up the child

• The child may be sweating, hyperventilating and tachycardic with dilated pupils

• May last 10 - 20 minutes, then the child goes back to sleep

• Looks very similar to emergence delirium with agitation

EEG and emergence delirium

• 64 Channel EEG during anaesthesia and recovery

• Sevoflurane anaesthesia +/- caudal and/or fentanyl

Awake

• Frontal low voltage beta, Posterior Dominant Rhythm (alpha)

Anaesthetised

• Diffuse slow (delta) with some frontal alpha

Pre-arousal, indeterminate EEG

Anaesthetised, slow wave EEG

Gas off

Indeterminate state

• Diffuse mixed alpha and beta

Indeterminate state

• Diffuse mixed alpha and beta – gradual lower voltage and modulation

Pre-arousal, indeterminate EEG

Anaesthetised, slow wave EEG

Delirium with agitation

Delirium without agitation

Calm awake Drowsy

1631

Sleep spindles

K complexes

K complexes & hypnopompic hypersynchrony

Pre-arousal, indeterminate EEG

Anaesthetised, slow wave EEG

Delirium with agitation

Delirium without agitation

Calm awake Drowsy

1631

EEG during delirium

• No specific EEG patterns

• Diffuse theta, no “sleep transients”

• Diffuse theta with PDR alpha and frontal beta

• Diffuse theta and frontal alpha

• Mixed “awake” and “asleep” features

• Some similarity to night terror

Delirium

• Diffuse theta with frontal EMG and no transients

EEG after propofol

• No delirium

• All had sleep like transients before awakening

Mechanism?

• Anaesthetics work via multiple mechanisms

• Mechanism is different depending on drug and concentration

• Some act via sleep-like mechanisms

• Perhaps these are less likely to produce delirium?

• Delirium occurs when the brain “wakes up” in a disorganised way

• Why do children get agitation with delirium? Maybe they are more anxious and unable to adapt

Prevention and management

At risk

• Preschool age

• Sevoflurane or desflurane

• Male

• ENT surgery?

• Pain?

• Pre-op anxiety?

Prevention

• Propofol• Infusion

• Bolus at end

• Alpha 2 agonsists

• Analgesia

• Dexamethasone

• Ketamine

• Gabapentin

• Less evidence: midazolam

Prevention – non pharmacologic

• Pre-op preparation – little evidence

• Let them wake up without being disturbed?

Management

• Little evidence

• Identify and treat any causes for agitation• Pain, fear, cold, hunger, full bladder

• Propofol

• Midazolam?

Summary

• Emergence agitation

• Emergence delirium

• Emergence delirium with agitation

• May be related to parasomnias

• May be linked to emergence that doesn’t enagage sleep path ways

• Propofol most effective

Thank you