acute stridor in children dr james peerless january 2015
TRANSCRIPT
Acute Stridor in Children
Dr James PeerlessJanuary 2015
Objectives
• Anatomy and Physiology• Assessment• Common Causes– Viral croup– Epiglottitis– Bacterial tracheitis– Retropharyngeal or tonsillar abscess– Foreign body
• Management
RCoA SyllabusAnnex 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 ObstructionInspiratory 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 BreathingVentilatory frequency Infant >50
Child >30
Effort Infant: head-bobbing, nasal flaringChild: see-saw chest and abdomen, recession (subcostal, intercostal, sternal, tracheal tug), nasal flaring
Posture Infant: Arching backwardsChild: Tripod
Noise Grunting (to generate auto-PEEP)WheezingStridor
Ineffective breathing Hypoxia & hypercarbia tachcardia, sweating, agitation, confusion, pallor
Impending respiratory arrest Reduced GCSApnoeic epsiodesSilent chestBradycardia
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 ScoreScore 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 pre-
vertebral 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) Nebulised adrenaline 1:1000.b) Oral dexamethasone.c) Nebulised dexamethasone.d) Nebulised budesonide. e) Inhaled Heliox.
MCQs
2. The presentation of bacterial tracheitis differs from epiglottis in that:
a) Stridor is inspiratory. b) There is dysphagia and drooling. c) The patient can lie flat. d) 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.