Upper Airway Obstruction & The Stridulous Child

The curriculum asks for us to know 'the management of acute airway obstruction including croup, epiglottitis and inhaled foreign body'.

There is a separate dedicated page on management of inhaled foreign body; this page will focus more on infective causes of upper airway obstruction.

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Various childhood respiratory tract infections may progressive to life-threatening airway obstruction

The child with stridor represents a challenge as any agitation, including examination or IV cannulation, may precipitate complete obstruction
Early, experienced involvement of ENT and anaesthetic teams is required

Bacterial	Viral	Non-infective
Tracheitis	Croup	Inhaled foreign body
Epiglottitis	Bronchiolitis	Anaphylaxis
Retropharyngeal abscess	Glandular fever	Tumours
Uvulitis		Vocal cord dysfunction

Disease	Age	Pathogen	Key clinical features	Management
Bacterial tracheitis		S. aureus	Thick mucopurulent secretions Absent drooling/dysphagia Can lie flat	Antibiotics
Epiglottitis	2 - 6yrs	H. influenzae type b	No viral prodrome Drooling, dysphagia Leaning forward helps	Antibiotics
Croup	6m - 3yrs	Parainfluenza (RSV Adenovirus Coronavirus)	Viral prodrome and slow deterioration Sitting upright Barking cough	Nebulised adrenaline Steroids (oral/nebulised)
Bronchiolitis	<2yrs	Respiratory syncitial virus	Viral prodrome No stridor	Supportive: oxygen, IV fluid, NG feeding
Retropharyngeal abscess		Staphs & Streps Respiratory anaerobes e.g. Fusobacteria, Prevotella	Limited neck movement	Drainage Antibiotics
Uvulitis	Any age	Group AStrep Haemophilus, Streptococcus Fusobacterium	Foreign body sensation in throat, worse when lying down	Supportive care Antibiotics

A rare, life-threatening infection most commonly caused by Staph. aureus, although Streptococci and Haemophilus may also be causative agents

Clinical features

Natural progression involves 2 - 3 days of viral URTI prodromal symptoms
This is followed by a rapid clinical deterioration over 8 - 10hrs

There is airway compromise and stridor from:

Sub-glottic oedema
Thick mucopurulent secretions

Other features:

Cough
Toxic appearance
High pyrexia

istinguishable from epiglottitis by typically an absence of drooling or dysphagia and the ability to lie flat

Management

Often require I&V due to either existing airway obstruction or possibility for rapid deterioration
Regular tracheal suction
Bronchoscopy to remove pseudomembranous exudates (to send for MC&S)
Antibiotics e.g. IV co-amoxiclav (30mg/kg) or ceftriaxone for suitable Gram positive cover
No evidence to support use of steroids

Inflammation of the epiglottis normally affecting those 2-6yrs old
Oedema collects below the stratified squamous epithelium on the anterior (superior) surface of the cartilage causing airway narrowing and stridor

Significantly less common following the introduction of routine Haemophilus influenzae type b vaccine
Can still be caused by Hib (vaccine failure), other Haemophilus subtypes or other organisms e.g. Streptococci

Clinical features

Lacks antecedent viral symptoms
Abrupt onset and short history of:

High fever
Stridor
Drooling
Dysphagia & odynophagia
Respiratory distress

Child may prefer leaning forward to keep their airway opens
Cough is typically absent

Management

Avoid excessive intervention e.g. cannulation, forcing oxygen therapy, can worsen respiratory distress and airway obstruction
I&V often required; may be associated with lower mortality than those who undergo attempted medical management only
Better to ensure adequate resources are available prior to intervening e.g.:

Senior anaesthetic/ICU presence
Presence of senior ENT team in case of need for emergency tracheostomy
Suitable airway equipment, anticipating a difficult airway
Move patient to a suitable location e.g. theatres
IV antibiotics drawn up ready to give (e.g. IV co-amoxiclav 30mg/kg)

May require 2-3 days intubated - mandatory cuff leak check prior to extubation

Acute airway obstruction from tonsillitis is rare, although may occur if there is associated peritonsillar/retropharyngeal abscess formation
Typically caused by multiple organisms, including Group A Strep, Staph aureus or respiratory anaerobes such as Fusobacteria and Prevotella

Pathophysiology

A potential peritonsillar space exists bounded by the palatoglossal and palatopharyngeal arches, and the superior constrictor muscle
Tonsillitis causes local cellulitis, which can lead to organised abscess formation leading and a peritonsillar abscess

The retropharyngeal space extends from the skull base to the posterior mediastinum, bounded by layers of deep cervical fascia
It contains lymph nodes which drain the nasopharynx, adenoids, sinuses and middle ear
Abscesses in the retropharyngeal space therefore can occur following URTI (50% of cases), as well as pharyngeal trauma (e.g. dentistry, laryngoscopy)

Physical expansion of the abscess(es) causes airway obstruction

Clinical features

Both peritonsillar and retropharyngeal abscesses present similarly, with:

Severe (sometimes unilateral) sore throat
Fever
Change in voice
Dysphagia
Drooling
Trismus (due to spasm of the medial pterygoid muscle)
Tonsillar swelling ± deviation of the uvula or palatal structures
Neck swelling/lymphadenopathy
A distinguishing clinical feature is the presence limited neck movement ± torticollis
Chest pain due to mediastinitis (retropharyngeal abscess)

CT with contrast can delineate between peritonsillar and retropharyngeal abscesses, although is often not necessary

Management

IV antibiotics with suitable Gram-positive and anaerobic cover
Surgical drainage of the abscess
May require I&V with ENT present and plan for difficult airway due to distorted airway anatomy
Consider tonsillectomy to reduce risk of local vascular erosion or aspiration

An acute inflammation of the uvula which can occur at any age
An infectious aetiology is typically due to Group A Streptococcus, Haemophilus influenzae, Strep. pneumoniae or Fusobacterium
Can occur following other inflammatory aetiologies:

Aetiology of uvulitis

Thermal injury

Iatrogenic trauma e.g. endotracheal intubation, upper airway suctioning, endoscopy

Vasculitis

Quincke's disease (primary angioedema of the uvula)

Marijuana or tobacco smoking

Allergic reactions

Clinical features

Fever
Pain
Dysphagia
Drooling
Foreign body sensation in throat, worse when lying down
Swollen erythematous uvula ± exudate

Respiratory distress is uncommon although can have coalescing epiglottitis

Management

Supportive treatment
Avoid unduly distressing the patient
IV antibiotics if infectious uvulitis suspected

A viral laryngotracheobronchitis and the most common cause of acute stridor in children
Occurs due to oedema of the epithelial layer of the upper airway
Most commonly due to Parainfluenza (types 1-3) although RSV, adenovirus and coronavirus may be responsible

Clinical features

48hrs of viral prodrome with nasal congestion, rhinorrhoea and coryza
Progression to:

Fever
Classic 'barking' cough
Stridor
Hoarse voice
Respiratory distress
Hypoxia

Preference for sitting upright

Management

Can use scoring systems to help stratify patients by severity e.g. Westley croup score
Mostly supportive although tracheal intubation sometimes necessary

Steroids reduce length of stay and readmission rates

Dexamethasone 0.15mg/kg PO/IM/IV ± further dose 12hrs later (non-inferior to higher doses e.g. 0.3 - 0.6mg/kg)
Budesonide 2mg nebulised
Prednisolone 1mg/kg PO once daily for 3 days although may be less efficacious than dexamethasone due to its shorter half life

Adrenaline e.g. 0.4-0.5ml/kg 1:1,000 nebulised (max 5ml)

Causes a significant albeit transient clinical improvement
Can be used as a bridge in severe cases in order to get steroids on board
A repeat dose can be given after 30mins but doing so should prompt senior anaesthetic/ICU/ENT involvement

No evidence for salbutamol, humidified oxygen or heliox
If intubation is required for croup, there is typically a long time before extubation is possible e.g. 7 - 10 days

A common, usually self-limiting, LRTI caused by Respiratory syncytial virus, typically affecting those <2yrs
Patients at higher risk include:

Ex-premature infants with chronic lung disease
Infants < 3 months of age
Congenital cardiac disease
Immunodeficiency

Clinical features

Prodrome over a few days
Acute presentation of:

Cough
Rhinorrhoea
Low-grade fever

Stridor is typically absent

Management takes the form of:

Supportive care
Oxygen therapy
Potential invasive ventilation

Supportive care

No routine upper airway suctioning, unless:

Airway secretions causing respiratory distress or feeding difficulties
Apnoea, even without obvious airway secretions

No routine blood gas testing, unless:

Severe worsening respiratory distress (F_iO₂ >0.5)
Impending respiratory failure

Give fluids by NG or OG tube if unable to take enough fluid by mouth

E.g. 100mls/kg/day

Consider IV fluids if above NGT regime poorly tolerated or significant WOB despite NG feeding
0.9% NaCl + 5-10% dextrose at 75mls/kg/day
Daily U&E whilst on IV fluid
Avoid positive fluid balance e.g. with diuretics

Consider nasopharyngeal aspirate (NPA) for microbiological testing
Consider caffeine if <3months old

Oxygen therapy

Provide supplemental oxygen therapy if:

<6 weeks or underlying health conditions and SpO₂ <92%
>6 weeks old and SpO₂<90%

E.g. high flow humidified nasal oxygen 2L/kg

Consider CPAP in those with impending respiratory failure
May require invasive ventilation if deteriorating

Lower threshold for I&V if premature, underlying cardiac, respiratory or neuromuscular disease or underlying immunodeficiency

Post-invasive ventilation management

Respiratory physiotherapy with 0.5-1ml/kg saline lavages to aid secretion clearance
Initial ventilatory strategy:

PIP 15cmH₂O
PEEP ≥5cmH₂O (may require 6-8cmH₂O if evidence of CXR collapse)
T_i 0.8 - 1.0s
RR <30

If still oxygenating poorly consider higher PEEP, prone ventilation or lower saturations target to >88%
If still ventilating poorly consider higher minute ventilation or permissive hypercapnoea to pH >7.25
Discuss with local tertiary unit e.g. SORT

Therapies not recommended for bronchiolitis

Bronchodilators: salbutamol, ipratropium, montelukast
Antibiotics
Adrenaline
Steroids (systemic or inhaled)
Hypertonic saline

General management of the child with upper airway obstruction

Recognise and declare an urgent or emergent situation
Mobilise consultant ENT surgeon and anaesthetist
Avoid distressing the child with examination, parental separation, forced therapy or cannulation
Commence non-threatening oxygen therapy
Inform theatres and transfer to theatres when safe to do so

As with inhaled foreign bodies, there are advantages and disadvantages to both gas and intravenous inductions
Regardless of chosen technique, senior anaesthetic and ENT personnel should be present prior to starting

Gas induction	IV induction
Avoids need for awake cannulation, which may be distressing	Familiar technique
Lower risk of apnoea due to slow onset of anaesthesia	Rapidly overcomes airway reflexes so ↓ coughing
Progression to complete airway obstruction prevents delivery of further anaesthesia thus causing the child to wake up i.e. automatic reversibility	Depth of anaesthesia uncoupled from airway patency
Volatile agents are bronchodilatory	Optimal oxygenation
	NMBA improves ventilating conditions
V/Q and CV effects of a suitable depth of anaesthesia needed to obliterate airway reflexes prior to intubation	Necessitates awake cannulation (if not already)
May be inappropriately slow in critical upper airway obstruction

For IV induction, use ketamine 1-2mg/kg IV and rocuronium 1mg/kg IV

Follow SORT/MAST ± DAS guidelines for intubation

No more than four attempts at laryngoscopy by anaesthetic team
If anaesthetic team can't intubate consider ENT-attempted intubation e.g. using Lindholm laryngoscope + Hopkins road
If still failing to attempt tracheostomy

IV access with bloods for FBC, biochemistry and blood cultures if gas induction
NG or OG tube to decompress stomach and improve oxygenation/ventilation
Commence broad-spectrum antibiotics ± steroids
Consider swabbing epiglottis, nose/throat for microbiology
Consider XR or CT if diagnosis uncertain
Arrange PICU retrieval