Acute Stridor in Children Dr James Peerless January 2015 Objectives • Anatomy and Physiology • Assessment • Common Causes – Viral croup – Epiglottitis – Bacterial tracheitis – Retropharyngeal.

Report
Acute Stridor in Children
Dr James Peerless
January 2015
Objectives
• Anatomy and Physiology
• Assessment
• Common Causes
– Viral croup
– Epiglottitis
– Bacterial tracheitis
– Retropharyngeal or tonsillar abscess
– Foreign body
• Management
RCoA Syllabus
Annex B
• PA_BK_08 Describes the management of acute airway obstruction
including croup, epiglottitis and inhaled foreign body
• AN_BK_01 Mouth, nose, pharynx, larynx, trachea, main bronchi,
segmental bronchi, structure of the bronchial tree; age-related changes
from the neonate to the adult
Annex C
• PA_IK_15 Explains the principles of stabilisation and safe transport of
critically ill children and babies
• EN_IK_17 Recalls/explains the principles underlying the use of helium
• EN_IK_11 Explains the principles of the recognition and appropriate
management of acute ENT emergencies, including bleeding tonsils,
epiglottis, croup, and inhaled foreign body
Anatomy & Physiology of the
Normal Airway in Children
Stridor
“Stridor is the harsh, vibratory sound produced
when the airway becomes partially
obstructed.”
Stridor
Level of Obstruction
Inspiratory
Above cords/extrathoracic;
croup, epiglottitis
Expiratory
Below cords/intrathoracic; FB
Biphasic
At or below cords; FB, bact.
tracheitis
The Infant Airway
• Upper and lower airways are small
• Prone to occlusion
– Secretions
– Oedema
• H-P equation
– Laminar flow rate most affected by changes to
vessel callibre
– Reduced callibre  reduced flow, increased WoB
The Infant Airway
• Upper and lower airways are small
• Prone to occlusion
– Secretions
– Oedema
• H-P equation
– Laminar flow rate most affected by changes to
vessel callibre
– Reduced callibre  reduced flow, increased WoB
The Infant Airway
• Thoracic cavity underdeveloped and
compliant
– Cartilaginous ribs
– Perpendicular to vertebrae
– Immature intercostal/accessory muscles
– Diaphragm-dependent
• Higher ratio of fatigable muscle fibres
• Increased WoB  recession
The Infant Airway
• High metabolic rate
• Increased O2 demand
• Smaller FRC
• All these factors predisposes the infant to
rapid deterioration
Assessment
• Disturb as little as possible
– Crying and agitation  increased effort
– Don’t examine the airway
– Don’t cannulate
• Allow to adopt comfortable position
• Assess degree of compromise
–
–
–
–
Inspection
Gentle examination
SpO2
Lab. tests and radiology
Increased Work of Breathing
Ventilatory frequency
Infant >50
Child >30
Effort
Infant: head-bobbing, nasal flaring
Child: see-saw chest and abdomen, recession
(subcostal, intercostal, sternal, tracheal tug),
nasal flaring
Posture
Infant: Arching backwards
Child: Tripod
Noise
Grunting (to generate auto-PEEP)
Wheezing
Stridor
Ineffective breathing
Hypoxia & hypercarbia  tachcardia,
sweating, agitation, confusion, pallor
Impending respiratory arrest
Reduced GCS
Apnoeic epsiodes
Silent chest
Bradycardia
Assessment
• Mobilise help early
– Senior anaesthetist
– ENT
– Theatre staff
Viral Croup
Viral Croup
• Laryngotracheobronchitis
• 80% of stridor cases (2% admitted)
• Parainfluenza virus
– Also: ’Flu A+B, RSV, rhinovirus
• 6m – 3y (peak 2y)
Viral Croup
• Symptoms
– 2-3 of URTI symptoms
– Barking cough
– Low-grade pyrexia
– Inspiratory stridor
• Assessed by Croup score
Croup Score
Score
0
1
2
Breath sounds Normal
Harsh, wheeze Delayed
Stridor
None
Inspiratory
Biphasic
Cough
None
Hoarse cry
Bark
Recession
None
Flaring,
suprasternal
Flaring,
suprasternal
and intercostal
Cyanosis
None
In air
In O2 40%
Croup Score
• Mild
– 0-3
• Moderate
– 4-6 (requires HDU)
• Severe
– 7+ (requires intubation)
Anaesthetic Management Plan
• Remember ABC…
• Assessment and resuscitation
• Help and mobilisation of services
• Serial assessments
• Treatment
–
–
–
–
Humidified gases
Steroids
Adr. Nebs. (0.5mL.kg-1 1:1000, max. 5mL)
Heliox
Anaesthetic Management Plan
• AIRWAY
– Assess obstruction; is intubation warranted immediately?
• BREATHING
– Assess degree of respiratory distress
– O2, SpO2
• CIRCULATION
•
•
•
•
•
Avoid upsetting child
Transfer to theatres
Inhalational induction with child sat upright
O2 and sevoflurane
Low-level CPAP can aid obstruction
Anaesthetic Management Plan
• Slow induction time (alveolar ventilation is restricted)
• Ensure adequate depth of anaesthesia prior to IV
access and airway manipulation
• ENT team on standby for emergency tracheostomy
• Swap ETT for nasal tube if possible (PICU transfer)
• Once stable:
–
–
–
–
–
CXR
NG
Sedate and IPPV
IV fluids
Blood and laryngeal cultures, and antibiotics.
Epiglottitis
Epiglottitis
• Life-threatening emergency
• H. influenzae (type B) – now rare due to Hib
vaccine (1992)
• 2-6y (peak at 3y)
• Fulminant onset and toxic appearance of child
• Rapid and high fever, dysphagia and stridor,
drooling.
• Child will often lean forward with jaw and tongue
hanging down.
Epiglottitis
•
•
•
•
•
Inhalational induction, as per croup
ENT surgeon on standby
Sitting position
Follow the bubbles
1.0mm ID smaller ETT
Epiglottitis
Bacterial Tracheitis
Tracheitis
• S. aureus, H. influenzae, streptococci,
Neisseria
• Mild 2-3d URTI, followed by rapid
deterioration – high fever and respiratory
distress
• Copious tracheal secretions
• Hoarse voice, and stridor
• Obstruction can occur secondary to oedema
or due to debris
Tracheitis
• Similar assessment and management to
epiglottitis.
• Bronchoscopy often required to remove
debris from airway.
Abscess
Abscesses
• Retropharyngeal
– Form in space between post. pharyngeal wall and prevertebral fascia
• Tonsillar
• Organisms
– Staphylococci and streptococci.
• Unwell child; limited neck movements, drooling,
trismus
• Oedema and swelling  upper airway obstruction
• Care must be taken to avoid rupture and subsequent
pus aspiration during intubation.
Foreign Body
Foreign Body
• Commonest between ages 1-2y
• Often of sudden onset with choking, but
unwitnessed events can mimic asthma
• Partial obstruction of lower airways can cause
ball and valve effect  pneumothorax and
surgical emphysema.
Foreign Body
• Timing weighing up urgency against fasting.
• Rigid bronchoscopy
• Dexamethasone and Adr. nebs will help
reduce post-op. swelling
MCQs
1. Which of the following have been shown to be
effective in the treatment of moderate to severe
viral croup in children?
a)
b)
c)
d)
e)
Nebulised adrenaline 1:1000.
Oral dexamethasone.
Nebulised dexamethasone.
Nebulised budesonide.
Inhaled Heliox.
MCQs
2. The presentation of bacterial tracheitis differs
from epiglottis in that:
a)
b)
c)
d)
Stridor is inspiratory.
There is dysphagia and drooling.
The patient can lie flat.
There is an antecedent history of an upper
respiratory tract infection.
e) Paroxysms of coughing produce copious
tenacious secretions.
MCQs
3. In the management of a child with epiglottitis:
a) A lateral X-ray of the neck is needed to confirm the
diagnosis.
b) Direct inspection of the epiglottitis using a tongue
depressor will show a swollen, red epiglottis.
c) The child should be anaesthetised with a rapid
sequence induction.
d) Nebulised adrenaline will help ease respiratory
distress.
e) Peak incidence is at 3 years of age.
MCQs
4. When securing the airway of a child with upper
airway obstruction:
a) Inhalational induction of anaesthesia is rapid.
b) Anaesthesia should be induced with a volatile
agent in an oxygen-nitrous oxide mixture.
c) Sevoflurane may be used safely.
d) It is best to exclude parents to avoid distress.
e) It essential to have intravenous access before
induction.
SAQs
• You are called to assess a 2-year-old girl in the ED
whose mother describes a 4-day history of malaise,
low-grade pyrexia and worsening cough. She has now
developed stidor and is becoming increasingly agitated.
(a) List the differential diagnoses of acute stridor in this
child (20%)
(b) What would be the indications for airway intervention
in this child? (10%)
(c) Following diagnosis, describe your management plan
for this child. (70%)
Reference
• Maloney E, Meakin G. Acute Stridor in
Children, CEACCP. 2007 7(6) 183-6
• Maloney E, Meakin G. Acute Stridor in
Children - MCQs, CEACCP. 2007 7(6) 215
• Shorthouse J, Barker G, Waldmann. SAQs for
the Final FRCA, 2011 Oxford University Press,
Oxford.

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