Croup (Laryngotracheobronchitis)

Quick Answer

Answer: Croup is acute viral laryngotracheobronchitis causing subglottic airway oedema in children aged 6 months to 3 years. Classic triad: barking seal cough, inspiratory stridor, hoarseness. Severity assessed using Westley Croup Score. Management: dexamethasone 0.15-0.6 mg/kg oral/IV (all severities), nebulised adrenaline 0.5 mL/kg 1:1000 for moderate-severe (max 5 mL). Observe 2-4 hours after adrenaline for rebound. Admit if stridor at rest post-treatment, Westley ≥3, or social factors. Heliox may help severe cases. Mist therapy ineffective. Most recover within 48-72 hours.

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ACEM Exam Focus

Exam Focus: Written Exam (SAQ): Westley score interpretation, escalation criteria, adrenaline/steroid dosing, discharge vs admission decisions, differential diagnosis of stridor, complications (epiglottitis, bacterial tracheitis, foreign body)

OSCE Stations: Paediatric airway assessment, managing distressed child, communication with anxious parents, administering nebulised adrenaline, escalation to PICU

Viva Domains: Pathophysiology of subglottic oedema, viral aetiologies, corticosteroid pharmacodynamics, adrenaline mechanism, Westley scoring, exclusion of red flags, Indigenous health considerations, remote/rural management

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Key Points

1. Peak age 6 months to 3 years (most commonly 18-24 months) due to small subglottic airway diameter
2. Parainfluenza virus (type 1 and 2) causes 75% of cases; other causes include RSV, influenza, adenovirus
3. Westley Croup Score is the standard validated severity assessment tool (0-17 points)
4. Dexamethasone (0.15-0.6 mg/kg) benefits ALL severity grades; oral route preferred
5. Nebulised adrenaline (0.5 mL/kg of 1:1000) provides temporary relief (2-4 hours) for moderate-severe croup; observation required for rebound
6. Admission criteria: stridor at rest after treatment, Westley ≥3, oxygen requirement, social concerns
7. Heliox (helium-oxygen) may reduce work of breathing in severe cases but not standard care
8. Mist/humidified air has NO evidence of benefit (Cochrane review)
9. Red flags: altered consciousness, cyanosis, silent chest, decreased air entry, rapidly progressive symptoms
10. Indigenous children have 2-3x higher rates of admission and ICU care due to social determinants of health

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Epidemiology

Croup is the most common cause of acute upper airway obstruction in children aged 6 months to 3 years, accounting for 3-6% of paediatric ED presentations annually. The incidence is approximately 4-6 per 100 children per year in this age group.

Seasonal Pattern:

• Autumn and early winter (April to June in Australia, October to December in northern hemisphere)
• Parainfluenza virus type 1 causes autumn peaks
• Parainfluenza virus type 2 causes biennial spring peaks

Age Distribution:

• 90% of cases occur between 6 months and 3 years
• Peak incidence: 18-24 months
• Rare in infants below 6 months (protective maternal antibodies, larger subglottic diameter relative to airway length)
• Rare in children above 6 years (larger airway diameter, viral immunity)

Aetiological Agents:

• Parainfluenza virus (type 1, 2, 3): 75% of cases
• Respiratory syncytial virus (RSV): 10-15%
• Influenza A and B: 5-10%
• Adenovirus: 5%
• Rhinovirus, metapneumovirus, coronavirus: below 5%
• Bacterial superinfection rare but causes severe complications (bacterial tracheitis)

Indigenous Health Disparities:

• Aboriginal and Torres Strait Islander children experience 2-3x higher rates of hospitalisation for croup
• Higher proportion of ICU admissions and mechanical ventilation requirements
• Contributing factors: crowded housing, tobacco smoke exposure, limited healthcare access, comorbidities (chronic lung disease, prematurity)
• Māori children in New Zealand also experience increased hospitalisation rates (RR 1.8)

Remote/Rural Considerations:

• Rural EDs have higher admission rates due to lack of observation facilities
• Longer transport times to tertiary centres increase risk of deterioration
• RFDS retrieval for severe cases with respiratory failure or need for PICU
• Limited access to heliox or ENT specialist support

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Pathophysiology

Croup is acute viral laryngotracheobronchitis characterised by inflammation and oedema of the subglottic region of the airway. The clinical manifestations result from the unique paediatric airway anatomy and the inflammatory response to viral infection.

Anatomical Considerations:

The subglottic airway is the narrowest segment in infants and young children, with several anatomical predispositions to obstruction:

1. Small Cross-Sectional Area: Subglottic diameter approximately 4-5 mm in infants, 7-8 mm in adults
2. Poiseuille's Law: Airway resistance inversely proportional to radius to the fourth power (R ∝ 1/r⁴)
3. Lack of Supporting Cartilage: Cricoid cartilage forms a complete ring; oedema causes circumferential narrowing
4. Loose Connective Tissue: Perichondrium allows significant oedema formation
5. Small Lumen Volume: 1 mm of circumferential oedema reduces cross-sectional area by 50-75% in infants vs 25% in adults

Inflammatory Cascade:

Viral infection of the respiratory epithelium triggers an inflammatory response:

1. Viral Entry: Parainfluenza virus binds to sialic acid receptors on respiratory epithelium
2. Cellular Damage: Direct viral cytopathic effect on epithelial cells
3. Inflammatory Mediator Release:
   • Histamine and bradykinin increase vascular permeability
   • Prostaglandins (PGE2, PGF2α) cause vasodilation
   • Leukotrienes (LTC4, LTD4, LTE4) increase mucus production
   • Cytokines (IL-6, IL-8, TNF-α) recruit neutrophils and macrophages
4. Oedema Formation: Increased capillary permeability → plasma exudation → subglottic oedema
5. Mucus Production: Goblet cell hyperplasia and increased mucin secretion
6. Narrowing: Circumferential oedema reduces airway diameter → increased airway resistance

Haemodynamic Consequences:

Airway obstruction produces characteristic clinical features:

Cough Mechanism:

The classic "seal bark" cough results from:

1. Narrowed Airway: Reduced diameter increases velocity of airflow through vocal cords
2. Oedematous Mucosa: Swollen arytenoid and false vocal cords vibrate during coughing
3. Mucous Plugs: Thick secretions in narrowed airway produce crackling quality

Stridor Pathophysiology:

• Inspiratory Stridor: Intrathoracic airway collapse during inspiration generates negative pressure; narrowed subglottic area creates turbulent flow
• Biphasic Stridor: Fixed obstruction present throughout respiratory cycle; indicates severe oedema
• Absent Stridor: "Silent chest"
• complete or near-complete obstruction; imminent respiratory failure

Recovery Process:

Resolution follows anti-inflammatory effects of corticosteroids:

• 2-6 hours: Reduced capillary permeability (corticosteroid-mediated)
• 6-12 hours: Decreased oedema, improved airway calibre
• 24-72 hours: Resolution of inflammation, return to baseline
• 7-10 days: Complete epithelial regeneration

Complications:

1. Respiratory Failure: Hypoxaemia, hypercapnia, respiratory acidosis
2. Pneumonia: Secondary bacterial infection (rare)
3. Bacterial Tracheitis: Staphylococcus aureus or Streptococcus pneumoniae superinfection
4. Pneumothorax/Pneumomediastinum: Barotrauma from increased intrathoracic pressure
5. Cardiac Compromise: Bradycardia from hypoxaemia, increased work of breathing

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Clinical Features

Croup presents with a characteristic constellation of symptoms that typically develop over 12-48 hours following a prodrome of upper respiratory symptoms.

Prodrome (1-3 days):

• Low-grade fever (37.5-38.5°C)
• Rhinorrhoea
• Sore throat
• Mild cough
• Conjunctivitis
• Irritability
• Decreased appetite

Cardinal Symptoms:

1. Barking Seal Cough

   • Sudden onset, typically worse at night
   • Harsh, brassy quality
   • Often precipitated by crying or agitation
   • May be absent in very mild or very severe cases

2. Inspiratory Stridor

   • High-pitched musical sound
   • Worse on inspiration, agitation, crying
   • Present at rest in moderate-severe cases
   • May become biphasic as obstruction worsens

3. Hoarseness

   • Loss of voice quality
   • Dysphonia (difficulty speaking)
   • Often preceding stridor onset

Physical Examination Signs:

Age-Specific Vital Signs (Normal vs Elevated):

Disease Progression Patterns:

1. Mild Croup: Occasional barking cough, no stridor at rest, minimal or no retractions, child playful
2. Moderate Croup: Frequent barking cough, stridor at rest, visible retractions, child alert but uncomfortable
3. Severe Croup: Frequent bark, prominent inspiratory/expiratory stridor, marked retractions, child agitated or lethargic
4. Impending Respiratory Failure: Depressed consciousness, pallor/cyanosis, decreased breath sounds, fatigue, apnoeic episodes

Classic Diurnal Pattern:

• Symptoms typically worsen at night
• "Croup hours": 10 pm to 4 am
• Improvement in morning
• May recur on subsequent nights for 2-3 nights

Differential Diagnosis:

⚠️ Warning: Red Flags Suggesting Alternative Diagnosis:

• Toxic appearance, high fever (above 39°C) → Epiglottitis or bacterial tracheitis
• Drooling, tripod posture, muffled voice → Epiglottitis
• Sudden onset without prodrome → Foreign body aspiration
• Progressive hoarseness without stridor → Recurrent respiratory papillomatosis
• No response to adrenaline/steroids → Alternative diagnosis
• History of prior intubation or neck surgery → Subglottic stenosis
• Associated skin lesions → Angio-oedema
• Age below 6 months or above 6 years → Atypical cause

Indigenous Health Considerations:

• Higher rates of recurrent croup episodes due to environmental exposures
• Greater prevalence of comorbidities (chronic lung disease, prematurity, malnutrition)
• Delayed presentation due to transport and access barriers
• Higher proportion of severe disease at presentation
• Cultural factors: Traditional healing practices, family decision-making involving elders

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Assessment

Systematic assessment of croup involves severity scoring, differential diagnosis evaluation, and identification of red flags requiring immediate intervention.

Primary Survey (ABCDE):

⚠️ Warning: Immediately Address:

• Respiratory distress with altered consciousness → Prepare for intubation
• Oxygen saturation below 90% → Supplemental oxygen
• Silent chest, cyanosis, bradycardia → Emergency airway management

A: Airway

• Assess airway patency: stridor quality (inspiratory vs biphasic)
• Identify airway compromise: drooling, inability to handle secretions
• Assess voice quality: hoarseness, aphonia, muffled voice
• Evaluate ability to speak: complete sentences vs short phrases vs single words

B: Breathing

• Respiratory rate: compare to age-appropriate normal
• Work of breathing: retractions, nasal flaring, accessory muscle use
• Breath sounds: air entry symmetry, presence of wheeze or crackles
• Oxygen saturation: target 94-98% in room air
• Capillary refill time: assess cardiovascular status

C: Circulation

• Heart rate: assess for tachycardia from respiratory distress vs fever
• Peripheral perfusion: capillary refill, skin temperature
• Blood pressure: hypotension indicates severe compromise
• Skin colour: pallor, cyanosis, mottling

D: Disability

• Level of consciousness: AVPU scale (Alert, Voice, Pain, Unresponsive)
• Response to parents: comfort-seeking vs inconsolable
• Agitation vs lethargy: agitation indicates distress; lethargy indicates fatigue

E: Exposure

• Temperature: fever patterns suggest bacterial infection
• Skin examination: urticaria, angio-oedema, bruising
• Cervical lymphadenopathy: localised suggests bacterial cause
• Neck position: tripod posture (epiglottitis), neck stiffness (retropharyngeal abscess)

Westley Croup Score:

The Westley Croup Score is the most widely validated tool for assessing croup severity and guiding management decisions. It evaluates five clinical parameters with a maximum score of 17.

Retraction Grading:

• Mild: Suprasternal or mild intercostal
• Moderate: Obvious intercostal and subcostal
• Severe: Suprasternal, intercostal, subcostal, and sternal

Severity Classification:

Interpretation Guidelines:

1. Reassess score after 30-60 minutes following initial treatment
2. Discharge threshold: Score ≤2 at 2 hours after adrenaline
3. Admission threshold: Score ≥3 at 2 hours after adrenaline
4. Escalation threshold: Score ≥8 or worsening despite treatment
5. PICU threshold: Score ≥12 or clinical deterioration

Investigations:

Routine Investigations NOT Indicated for Typical Croup:

1. Chest X-ray: Not recommended for typical croup

   • May show "steeple sign" (narrowing of subglottic airway) on AP view
   • Sensitivity and specificity low; does not change management
   • Consider only if foreign body aspiration suspected

2. Full Blood Count (FBC):

   • Usually shows mild lymphocytosis in viral croup
   • Not routinely indicated
   • Consider if bacterial superinfection suspected (high fever, toxic appearance)

3. Inflammatory Markers (CRP, ESR):

   • Not routinely indicated
   • Elevated markers suggest bacterial infection
   • Consider if differentiating from bacterial tracheitis

4. Viral Studies (PCR, swab):

   • Not needed for routine management
   • May be helpful for outbreak identification or infection control
   • Respiratory multiplex PCR available in some centres

5. Blood Cultures:

   • Not indicated for uncomplicated croup
   • Consider if bacterial tracheitis or sepsis suspected

Investigations for Atypical Presentations:

1. Chest X-ray:

   • Foreign body aspiration: unilateral hyperinflation, mediastinal shift
   • Bacterial tracheitis: irregular tracheal air column, pneumonic infiltrates
   • Retropharyngeal abscess: widening of prevertebral space on lateral neck X-ray

2. Lateral Neck X-ray:

   • Epiglottitis: swollen epiglottis ("thumbprint sign")
   • Retropharyngeal abscess: prevertebral space greater than 1/2 vertebral body width at C2

3. Flexible Nasopharyngolaryngoscopy:

   • Gold standard for visualising upper airway
   • Perform in controlled setting (OT with ENT)
   • Identifies epiglottitis, foreign body, subglottic stenosis

4. CT Neck:

   • Rarely indicated in acute setting
   • Consider for deep neck space infection or atypical anatomy

Point-of-Care Ultrasound (POCUS):

Emerging evidence for airway ultrasound in croup:

• Measures subglottic airway diameter
• Predicts severity and need for admission
• Limited availability and operator dependence
• Not yet standard of care

Differential Diagnosis Workup:

Red Flag Assessment:

⚠️ Warning: Immediate ENT/Paediatric Consultation Required For:

• Rapidly progressive symptoms within hours
• Inability to handle secretions, drooling
• High fever (above 39°C) with toxic appearance
• Cyanosis or oxygen saturation below 90%
• Altered level of consciousness
• Biphasic stridor with high-pitched sound
• Silent chest or decreased breath sounds
• History of foreign body aspiration or recent surgery

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Management

Management of croup is based on severity assessment using the Westley Croup Score. All patients receive corticosteroids, with nebulised adrenaline reserved for moderate-severe cases. The primary goals are reducing airway oedema, maintaining adequate oxygenation, and preventing respiratory failure.

General Measures:

1. Parental Presence: Allow parents to remain with the child; reduces child anxiety and improves oxygenation
2. Positioning: Upright position in parent's lap; avoid supine positioning
3. Minimal Handling: Reduce unnecessary examination to avoid agitation
4. Calm Environment: Dim lights, quiet room to reduce work of breathing
5. Hydration: Encourage oral fluids if able; IV fluids if unable to swallow
6. Monitoring: Continuous pulse oximetry, frequent reassessment of respiratory status
7. Antipyretics: Paracetamol (15 mg/kg) or ibuprofen (10 mg/kg) for fever and discomfort

Discontinued Therapies:

⚠️ Warning: Evidence-Based Recommendations:

• Mist/Humidified Air: Cochrane review shows NO benefit; no longer recommended
• Steam Therapy: Risk of scalds, no proven efficacy; contraindicated
• Antibiotics: Not indicated for viral croup; reserved for bacterial superinfection
• Decongestants/Expectorants: No evidence of benefit; may cause adverse effects

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Pharmacological Management

1. Corticosteroids

Indication: ALL severity grades of croup

Mechanism of Action:

• Decrease capillary permeability → reduced oedema formation
• Inhibit inflammatory mediator release (histamine, bradykinin, leukotrienes)
• Reduce cytokine production (IL-6, IL-8, TNF-α)
• Onset of action: 1-2 hours
• Duration of effect: 24-72 hours

Evidence:

• Cochrane review (Russell et al., 2018): Corticosteroids reduce croup severity by 50%, decrease hospital admissions by 80%, shorten length of stay by 12 hours
• Low dose (0.15 mg/kg) as effective as high dose (0.6 mg/kg) for mild-moderate croup
• Oral dexamethasone as effective as IM/IV; oral route preferred

Dosing:

Dexamethasone Preparation:

• Oral dexamethasone syrup: 2 mg/5 mL
• Maximum dose: 10 mg (regardless of weight)
• Concentration: 4 mg/mL (IV/IM formulation)
• Do not use dexamethasone elixir containing alcohol (preservative irritation)

Administration Considerations:

• Oral: Preferred route; can be mixed with juice or soft drink if needed
• IM: Use if vomiting; lateral thigh in infants
• IV: Use in critically ill or unable to administer orally
• Repeat dosing: Not routinely indicated; consider if symptoms recur after 24-48 hours

Contraindications:

• Relative contraindications: uncontrolled diabetes, active infection, severe hypertension
• Benefit outweighs risk in acute croup; use clinical judgment

Adverse Effects:

• Short-term use: rare; minimal risk
• Hyperglycaemia in diabetic patients (monitor glucose)
• Mood changes, agitation
• Delayed wound healing (not clinically significant)

2. Nebulised Adrenaline (Epinephrine)

Indication: Moderate-to-severe croup (Westley ≥3)

Mechanism of Action:

• Alpha-1 adrenergic receptor agonism → vasoconstriction of subglottic mucosa
• Reduced capillary permeability → decreased oedema
• Beta-2 adrenergic receptor agonism → bronchodilation
• Onset of action: 5-15 minutes
• Duration of effect: 2-4 hours

Evidence:

• Cochrane review (Bjornson et al., 2013): Adrenaline improves croup score by 2-3 points within 30 minutes
• Effect is temporary; does not alter natural history or total length of stay
• Rebound effect possible after 2-4 hours; observation required

Dosing:

Alternative Weight-Based Dosing:

• 0.5 mL/kg of 1:1000 solution
• Maximum: 5 mL
• Equivalent to 0.5 mg/kg adrenaline

Administration:

• Dilute in 3-5 mL normal saline
• Administer via face mask with oxygen (6-8 L/min)
• Child in parent's lap, calm environment
• Continuous reassessment during administration

Response Assessment:

• Improved stridor within 10-15 minutes
• Decreased retractions
• Improved air entry
• Reduced respiratory rate
• Improved oxygen saturation

Observation Period:

• Minimum 2-4 hours after adrenaline administration
• Monitor for rebound worsening (usually occurs 2-4 hours post-dose)
• Reassess Westley score at 30, 60, 120, and 240 minutes

Second Dose Indications:

• Persistent stridor at rest at 2 hours after first dose
• Worsening Westley score after initial improvement
• Recurrence of severe symptoms after discharge from observation

Contraindications:

• Absolute: None in emergency setting
• Relative: Severe cardiac arrhythmias, uncontrolled hypertension

Adverse Effects:

• Tachycardia, palpitations
• Tremor, agitation
• Hypertension (transient)
• Hypokalaemia (rare, high doses)

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Adjunctive Therapies

3. Helium-Oxygen (Heliox)

Indication: Severe croup (Westley ≥8) as adjunct to standard therapy

Mechanism of Action:

• Helium is less dense than nitrogen → reduces turbulent flow
• Decreases work of breathing by reducing airway resistance
• Improves laminar flow through narrowed airway
• Does not reduce oedema; symptomatic relief only

Composition:

• Heliox 70:30: 70% helium, 30% oxygen
• Heliox 80:20: 80% helium, 20% oxygen
• Higher oxygen percentage for hypoxaemic patients

Evidence:

• Small RCTs show improved croup scores and reduced work of breathing
• Not superior to nebulised adrenaline
• Limited availability, high cost, logistics challenges
• Not standard of care; use in PICU setting only

Administration:

• Requires non-rebreather mask or ventilator circuit
• Flow rates 10-15 L/min
• Continuous oxygen monitoring
• Cannot be used with nebulised adrenaline (helium interferes with nebulisation)

Contraindications:

• Hypoxaemia requiring high FiO2 (above 40-50%)
• Heliox cannot provide adequate oxygenation

4. Supplemental Oxygen

Indication:

• Oxygen saturation below 94%
• Significant respiratory distress
• Cyanosis or pallor

Administration:

• Humidified oxygen via nasal cannula or face mask
• Target saturation: 94-98% (avoid hyperoxia)
• Flow rate: 1-4 L/min (nasal cannula), 4-8 L/min (face mask)

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Escalation of Care

5. High-Flow Nasal Cannula (HFNC)

Indication:

• Persistent oxygen requirement despite standard oxygen therapy
• Moderate-severe work of breathing
• Avoidance of CPAP/NIV

Mechanism:

• Delivers heated, humidified gas at high flow (up to 2 L/kg/min)
• Provides positive airway pressure
• Washes out dead space
• Improves oxygenation and reduces work of breathing

Evidence:

• Emerging evidence for croup management
• Limited data; not standard of care
• May be useful in PICU setting

Contraindications:

• Severe respiratory distress requiring intubation
• Altered consciousness

6. Non-Invasive Ventilation (NIV)

Indication:

• Severe respiratory distress with impending failure
• Hypercapnia (PaCO2 above 50 mmHg)
• Respiratory acidosis (pH below 7.30)

Methods:

• Nasopharyngeal CPAP: 5-10 cm H₂O
• Bilevel CPAP (BiPAP): IPAP 12-16 cm H₂O, EPAP 6-8 cm H₂O

Contraindications:

• Altered consciousness
• Vomiting
• Airway obstruction above glottis
• Facial trauma

7. Intubation and Ventilation

Indication:

• Respiratory failure (hypoxaemia despite HFNC/NIV, hypercapnia with acidosis)
• Altered level of consciousness
• Complete airway obstruction
• Cardiac arrest

Airway Strategy:

1. Team Assembly: Paediatric intensivist, anaesthetist, ENT surgeon, PICU team
2. Equipment: Smallest ETT possible (usually 0.5-1 mm smaller than age-based size)
   • Age-appropriate ETT size: (Age/4) + 4
   • For croup: Use 1 size smaller to accommodate oedema
3. Induction: Ketamine 1-2 mg/kg IV (preserves airway reflexes, bronchodilation)
   • Alternative: Sevoflurane inhalational induction (maintains spontaneous respiration)
4. Paralysis: Rocuronium 1 mg/kg IV (after airway secured)
5. Tube Confirmation: Capnography, chest rise, bilateral breath sounds
6. Ventilation: Low tidal volumes (6-8 mL/kg), adequate PEEP (5-8 cm H₂O)
7. Sedation: Midazolam, morphine/fentanyl infusion
8. Humidification: Heated humidifier required

Cricothyroidotomy:

• Last resort if cannot intubate or ventilate
• Surgical cricothyroidotomy (children below 10-12 years)
• Needle cricothyroidotomy (temporary measure in neonates)

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Antimicrobial Therapy

Indication: Bacterial Superinfection Only

Bacterial Tracheitis:

• Empiric Therapy: Ceftriaxone 50-75 mg/kg IV daily (max 2 g)
• Add Vancomycin if MRSA suspected: 15 mg/kg IV q6h (max 500 mg)
• Adjust based on culture results (S. aureus, S. pyogenes, S. pneumoniae)

Epiglottitis:

• Ceftriaxone 50-75 mg/kg IV daily (max 2-4 g)
• Continue 7-10 days

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Discharge Planning

Discharge Criteria:

1. Westley Score ≤2 after 2-4 hours observation
2. No stridor at rest
3. Normal oxygen saturation (above 94% in room air)
4. Good oral intake
5. Reliable caregivers with transport
6. Patient received corticosteroids
7. Caregivers understand red flags and when to return

Parental Education:

1. Expected Course:

   • Symptoms may improve within 6-12 hours of steroids
   • Cough and hoarseness may persist 7-10 days
   • Noisy breathing may recur on subsequent nights (2-3 nights typical)

2. Home Care:

   • Encourage oral fluids
   • Maintain humidified environment (cool mist humidifier)
   • Paracetamol/ibuprofen for fever and discomfort
   • Keep child calm and upright

3. Red Flags - Return Immediately:

   • Stridor at rest
   • Difficulty breathing (fast breathing, retractions)
   • Blue or pale colour
   • Difficulty swallowing or drooling
   • High fever (above 39°C)
   • Lethargy or difficult to wake
   • No improvement or worsening after 24 hours

4. Follow-up:

   • General practitioner review in 24-48 hours
   • Return to ED if red flags develop
   • Consider referral to paediatrician for recurrent croup (≥3 episodes)

Prescriptions at Discharge:

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Admission Criteria

Absolute Indications for Admission:

1. Persistent Stridor at Rest after 2 doses of adrenaline
2. Westley Score ≥3 at 2-4 hours after initial treatment
3. Oxygen Requirement (SpO2 below 94% on room air)
4. Severe Respiratory Distress (Westley ≥8)
5. Altered Level of Consciousness (AVPU: P or U)
6. Rebound Worsening after adrenaline observation period
7. More than 2 doses of adrenaline required within 24 hours

Relative Indications for Admission:

1. Age below 6 months (higher risk of deterioration)
2. Underlying Comorbidities:
   • Prematurity, chronic lung disease
   • Congenital heart disease
   • Neuromuscular disorders
   • Immune deficiency
3. Social Factors:
   • Distance from hospital (more than 1 hour travel)
   • Inadequate transport
   • Parental anxiety, inability to monitor child
   • Non-English speaking caregivers (communication barrier)
4. Time of Presentation (late night discharge with unreliable follow-up)

Ward Admission vs PICU Admission:

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Indigenous Health Considerations

Aboriginal and Torres Strait Islander children and Māori children experience significant disparities in croup outcomes due to a complex interplay of social, environmental, and healthcare system factors.

Epidemiology:

• Hospitalisation Rate: Aboriginal and Torres Strait Islander children have 2-3x higher rates of hospitalisation for croup compared to non-Indigenous children
• ICU Admissions: Higher proportion require PICU admission and mechanical ventilation
• Length of Stay: Longer hospital stays on average (3-4 days vs 2 days)
• Mortality: Similar mortality but higher burden of severe disease

Contributing Factors:

1. Environmental Exposures:

   • Tobacco Smoke: Higher prevalence of household smoking; prenatal exposure increases risk
   • Crowded Housing: Overcrowding facilitates viral transmission
   • Wood Smoke: Solid fuel heating in remote communities increases respiratory irritation
   • Dust and Pollutants: Geographic location increases exposure to environmental triggers

2. Social Determinants of Health:

   • Socioeconomic Disadvantage: Lower income, education, employment
   • Food Security: Poor nutrition contributes to immune dysfunction
   • Housing Quality: Inadequate heating, ventilation, and dampness
   • Transport Access: Limited access to vehicle for medical care

3. Healthcare Access Barriers:

   • Geographic Isolation: Remote communities with delayed presentation
   • Cultural Barriers: Distrust of healthcare system, historical trauma
   • Communication Barriers: Language differences, health literacy
   • Fragmented Care: Transient populations, discontinuity of care

4. Comorbidities:

   • Chronic Lung Disease: Higher rates of asthma, bronchiectasis
   • Prematurity: Higher rates of preterm birth
   • Nutritional Deficiencies: Iron deficiency, vitamin D deficiency
   • Recurrent Infections: Higher burden of respiratory infections

Clinical Implications:

⚠️ Warning: Higher Index of Suspicion for Complications:

• Delayed presentation may result in more severe disease at arrival
• Higher risk of bacterial superinfection (tracheitis, pneumonia)
• Increased likelihood of requiring escalation to PICU
• Longer duration of symptoms post-treatment

1. Lower Threshold for Admission:

   • Consider admission for Westley score 2-3 (instead of 3+)
   • Lower threshold for observation period (4-6 hours vs 2-4 hours)
   • Consider social determinants when planning discharge

2. Enhanced Monitoring:

   • More frequent reassessment (every 30-60 minutes)
   • Continuous pulse oximetry even for mild cases
   • Consider longer observation period (4-6 hours minimum)

3. Comorbidities Screening:

   • Assess for chronic lung disease (asthma, bronchiectasis)
   • Evaluate nutritional status (growth parameters)
   • Screen for recurrent infections (immunodeficiency, chronic sinusitis)

4. Family-Centred Care:

   • Include extended family in decision-making (elders, grandparents)
   • Respect cultural practices and traditional healing
   • Use culturally appropriate communication (storytelling, visual aids)
   • Involve Aboriginal Health Workers or Māori Health Providers

Culturally Safe Communication:

1. Building Trust:

   • Introduce yourself and your role clearly
   • Ask about preferred communication style
   • Listen actively to family concerns and explanations
   • Respect family's knowledge and experience

2. Explain the Condition:

   • Use simple language and visual aids
   • Avoid medical jargon
   • Explain in context of "windpipe swelling" or "airway inflammation"
   • Use analogies consistent with cultural understanding

3. Discuss Treatment:

   • Explain benefits and risks of medications
   • Address concerns about corticosteroids
   • Discuss traditional healing practices (if used)
   • Integrate Western and traditional approaches where appropriate

4. Discharge Planning:

   • Provide written instructions in plain English
   • Use visual aids for red flags
   • Arrange GP follow-up with cultural liaison worker if available
   • Ensure transport arrangements are in place

Remote and Rural Considerations:

1. Local Health Worker Engagement:

   • Collaborate with Aboriginal Medical Services or rural GPs
   • Provide training for local health workers on croup assessment
   • Develop telehealth support pathways

2. Medication Supply:

   • Ensure local clinics have dexamethasone and adrenaline supplies
   • Provide age-appropriate dosing charts
   • Establish backup supply protocols

3. Retrieval Planning:

   • Early discussion with retrieval service (RFDS, aeromedical)
   • Clear criteria for transfer to tertiary centre
   • Consider family relocation (patient transfer vs family accompanies)

4. Follow-Up Arrangements:

   • Schedule telehealth review post-discharge
   • Coordinate with local AMS or rural health service
   • Provide clear communication to treating GP

Māori Health Considerations (New Zealand):

1. Tikanga and Kaitiakitanga:

   • Respect cultural protocols in patient care
   • Acknowledge the role of whānau (family) in decision-making
   • Incorporate concepts of manaakitanga (care and support)

2. Communication Style:

   • Use Māori Health Providers as cultural brokers
   • Allow time for whānau consultation
   • Respect cultural practices (karakia, waiata)

3. Health Literacy:

   • Use plain language and visual aids
   • Check understanding regularly
   • Provide written resources in appropriate languages

Data Collection and Quality Improvement:

• Document Indigenous status in medical records
• Track outcomes for Indigenous patients (length of stay, ICU admission, readmission)
• Identify disparities and implement targeted interventions
• Engage with Indigenous health organisations for quality improvement

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Remote/Rural Considerations

Croup management in remote and rural emergency departments presents unique challenges due to limited resources, delayed access to specialist care, and longer transport times. Adaptation of standard protocols is necessary to ensure patient safety.

Resource Limitations:

1. Staffing:

   • Limited paediatric experience among rural practitioners
   • No on-site paediatrician or intensivist
   • Single doctor/paramedic scenarios
   • Limited nursing support overnight

2. Equipment:

   • May not have paediatric-sized equipment
   • Limited availability of nebulisers, oxygen cylinders
   • No heliox or HFNC availability
   • Limited monitoring equipment (capnography)

3. Medications:

   • Stockouts of dexamethasone or adrenaline possible
   • Limited range of alternative steroids
   • No access to second-line therapies

4. Imaging:

   • Limited radiology access (no on-site X-ray)
   • Transfer required for imaging if indicated
   • Delayed interpretation of studies

Clinical Decision-Making in Remote Settings:

1. Lower Threshold for Transfer:

   • Consider transfer for Westley score ≥3 (instead of ≥4-5)
   • Earlier activation of retrieval service (within 1-2 hours of presentation)
   • Lower threshold for PICU transfer

2. Extended Observation Period:

   • Observe for 4-6 hours after adrenaline (vs 2-4 hours urban)
   • More frequent reassessment (every 30 minutes)
   • Continue observation overnight for late-night presentations

3. Early Administration of Corticosteroids:

   • Give dexamethasone immediately on recognition of croup
   • Do not delay for transfer or observation
   • Consider second dose at 24 hours if symptoms persist

4. Conservative Adrenaline Use:

   • Give adrenaline for moderate-severe cases (Westley ≥3)
   • Observe longer post-adrenaline (4-6 hours)
   • Lower threshold for second dose

Retrieval Considerations:

Criteria for Retrieval Request:

1. Urgent Retrieval (within 2-4 hours):

   • Westley score ≥8
   • Oxygen requirement (SpO2 below 92%)
   • Altered consciousness
   • Worsening despite adrenaline + steroids
   • Rebound worsening after adrenaline

2. Planned Retrieval (within 12-24 hours):

   • Persistent moderate symptoms (Westley 3-7)
   • Multiple adrenaline doses required
   • Underlying comorbidities
   • Social factors (distance, unreliable transport)

3. Non-Retrieval (Local Management):

   • Mild symptoms (Westley ≤2)
   • Excellent response to single dose adrenaline
   • Reliable caregivers with local follow-up
   • No red flags

Retrieval Preparation:

1. Stabilisation Before Transport:

   • Ensure maximum stability before departure
   • Give dexamethasone if not already given
   • Consider adrenaline dose before transport if needed
   • Ensure IV access for critically ill

2. Documentation:

   • Complete medical record with times, doses, responses
   • Westley score at multiple time points
   • Vital signs trends
   • Medication administration record

3. Communication:

   • Handover to retrieval team using ISBAR format
   • Clear description of current status and trajectory
   • Ongoing concerns and anticipated complications
   • Family considerations

4. Family Accompaniment:

   • Discuss whether family should accompany patient
   • Arrange family transport if needed
   • Consider cultural needs (family presence, elder involvement)

Telemedicine Support:

1. Indications for Telehealth Consultation:

   • Uncertain diagnosis or severity
   • Guidance on escalation
   • Transfer decision support
   • Cultural consultation with Indigenous health providers

2. Technical Considerations:

   • Ensure reliable internet connection
   • Test equipment before patient encounter
   • Have backup plan if connection fails

3. Documentation of Consultation:

   • Document time, consultant, recommendations
   • Record decision-making rationale
   • Include recommendation in transfer notes

Modified Protocols for Remote Settings:

RFDS (Royal Flying Doctor Service) Considerations:

1. Aeromedical Transport:

   • Altitude considerations (hypoxia risk)
   • Cabin pressure effects on airway oedema
   • Continuous monitoring during flight
   • Helium not available on most aircraft

2. Road Retrieval:

   • Long transport times (up to 6-8 hours)
   • Limited space for equipment and family
   • Bumpy roads may agitate child
   • Stop for reassessment if needed

3. Inter-Facility Transfer:

   • Clear handover to receiving hospital
   • Ensure transfer notes complete
   • Coordinate with PICU team
   • Provide family with information about destination

Quality Improvement in Remote Settings:

1. Audit and Feedback:

   • Track outcomes for croup patients
   • Identify missed diagnoses or delays
   • Review transfer appropriateness
   • Monitor adverse events

2. Training and Education:

   • Regular paediatric emergency training
   • Simulation scenarios for croup management
   • Cultural safety training
   • Telehealth training

3. Protocol Development:

   • Local protocols adapted to resources
   • Clear escalation pathways
   • Documentation templates
   • Transfer request protocols

4. Community Engagement:

   • Education about croup recognition
   • Transport planning for emergencies
   • Culturally appropriate health promotion
   • Collaboration with Aboriginal Medical Services

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Pitfalls and Pearls

Pitfalls:

1. Missing Alternative Diagnoses:

   • Assuming croup is always viral; missing bacterial tracheitis or epiglottitis
   • Overlooking foreign body aspiration with sudden onset
   • Dismissing high fever as "just viral"
   • Failing to consider angio-oedema in children with allergies

2. Inappropriate Discharge:

   • Discharging too early after adrenaline (rebound effect)
   • Ignoring social factors (distance, transport, caregiver reliability)
   • Discharging before corticosteroid effects manifest
   • Not ensuring caregivers understand red flags

3. Medication Errors:

   • Using adrenaline concentration incorrectly (1:1000 vs 1:10,000)
   • Under-dosing steroids (below 0.15 mg/kg)
   • Using inappropriate routes (IM when oral acceptable)
   • Missed doses in severe cases

4. Inadequate Monitoring:

   • Insufficient observation time after adrenaline
   • Missing rebound deterioration
   • Not reassessing Westley score after treatment
   • Ignoring vital sign trends

5. Cultural Insensitivity:

   • Dismissing Indigenous health concerns
   • Not including family in decision-making
   • Failing to use cultural liaison services
   • Not adapting communication style

6. Escalation Delays:

   • Late recognition of respiratory failure
   • Delayed activation of retrieval service
   • Not involving ENT early for suspected airway obstruction
   • Inadequate preparation for intubation

7. Inadequate Documentation:

   • Poor documentation of Westley scores over time
   • Not recording medication administration times
   • Failing to document handover to retrieval team
   • Missing family communication

Pearls:

1. Early Steroids Are Key:

   • Give dexamethasone immediately on recognition of croup
   • All severity grades benefit from steroids
   • Low dose (0.15 mg/kg) as effective as high dose
   • Oral route preferred unless vomiting

2. Adrenaline is Temporary:

   • Effect lasts 2-4 hours; observation required
   • Rebound effect possible; monitor closely
   • Second dose appropriate if symptoms recur
   • Does not change natural history

3. Westley Score is Your Guide:

   • Use objective scoring for severity assessment
   • Reassess at regular intervals
   • Guide management decisions based on score
   • Document scores over time

4. Calm Environment is Therapeutic:

   • Parental presence reduces work of breathing
   • Avoid unnecessary examination
   • Keep child upright in parent's lap
   • Dark, quiet room beneficial

5. Mist Therapy is Obsolete:

   • No evidence of benefit (Cochrane review)
   • Risk of scalds with steam
   • Do not use or recommend
   • Focus on evidence-based therapies

6. Discharge Planning is Critical:

   • Ensure caregivers understand red flags
   • Provide written instructions
   • Arrange reliable follow-up
   • Consider social factors

7. Cultural Safety is Mandatory:

   • Include family and elders in care
   • Use cultural liaison workers
   • Adapt communication style
   • Respect traditional healing practices

8. Remote Practice Requires Adaptation:

   • Lower threshold for admission and transfer
   • Extend observation period
   • Early activation of retrieval service
   • Use telemedicine for support

9. Red Flags Mean Action:

   • Stridor at rest after treatment → admit
   • Altered consciousness → prepare for intubation
   • Silent chest → emergency airway management
   • Biphasic stridor → severe obstruction

10. Family-Centred Care Improves Outcomes:

    • Educate parents about expected course
    • Address parental anxiety
    • Encourage parental involvement in care
    • Provide reassurance

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Viva Practice

Viva 1: Pathophysiology and Assessment

Examiner: "A 2-year-old presents with a barking cough and stridor. How do you approach this patient?"

Candidate: "I would immediately assess the child's airway, breathing, and circulation. My primary concern is differentiating croup from more serious causes of upper airway obstruction. I would assess for the classic croup triad: barking seal cough, inspiratory stridor, and hoarseness. I would check the child's level of consciousness, colour, and work of breathing. I would then calculate the Westley Croup Score to objectively assess severity. I would look for red flags that suggest alternative diagnoses: drooling, tripod posture, high fever, toxic appearance, sudden onset without prodrome, or muffled voice."

Examiner: "What is the pathophysiology of croup and why does it affect children more than adults?"

Candidate: "Croup is acute viral laryngotracheobronchitis causing subglottic airway oedema. The virus (usually parainfluenza) infects the respiratory epithelium, triggering an inflammatory response with release of histamine, bradykinin, prostaglandins, leukotrienes, and cytokines. This increases capillary permeability and causes oedema formation in the subglottic region.

Children are more susceptible because the subglottic airway is the narrowest part of their airway, with a diameter of only 4-5 mm. According to Poiseuille's law, airway resistance is inversely proportional to the radius to the fourth power, so small changes in radius cause large increases in resistance. Additionally, the cricoid cartilage forms a complete ring, and perichondrium allows significant oedema to form circumferentially. In adults, the larger airway diameter means that equivalent oedema causes less obstruction."

Examiner: "Explain the Westley Croup Score and how you use it."

Candidate: "The Westley Croup Score evaluates five clinical parameters with a maximum score of 17. Stridor is scored 0 for none, 1 if present with agitation, and 2 if present at rest. Retractions are scored 0 for none, 1 for mild, 2 for moderate, and 3 for severe. Air entry is scored 0 for normal, 1 for decreased, and 2 for markedly decreased. Cyanosis is scored 0 for none, 1 if present with agitation, and 2 if present at rest. Level of consciousness is scored 0 for normal and 5 if disoriented.

Severity classification is: 0-2 is mild, 3-7 is moderate, 8-11 is severe, and 12 or above indicates impending respiratory failure. The score guides management: mild croup gets dexamethasone only; moderate gets dexamethasone plus adrenaline; severe requires admission and possible PICU transfer; impending respiratory failure needs emergency airway management. I would reassess the score 30-60 minutes after treatment and 2-4 hours after adrenaline to assess response."

Examiner: "What are the red flags that would make you concerned about an alternative diagnosis?"

Candidate: "Red flags suggesting alternative diagnosis include: toxic appearance and high fever above 39°C (suggesting bacterial tracheitis or epiglottitis); drooling or inability to handle secretions (epiglottitis); tripod posture and muffled voice (epiglottitis); sudden onset without prodrome (foreign body aspiration); unilaterally decreased breath sounds (foreign body); neck stiffness or limited neck extension (retropharyngeal abscess); no response to adrenaline and steroids (alternative diagnosis); age below 6 months or above 6 years (atypical cause); and history of prior intubation or neck surgery (subglottic stenosis)."

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Viva 2: Pharmacological Management

Examiner: "What are your initial pharmacological treatments for croup?"

Candidate: "All children with croup should receive corticosteroids, regardless of severity. Dexamethasone is the preferred agent, dosed at 0.15-0.6 mg/kg orally, intramuscularly, or intravenously as a single dose. The oral route is preferred if the child is not vomiting. Evidence shows that low dose (0.15 mg/kg) is as effective as high dose (0.6 mg/kg) for mild to moderate croup. Corticosteroids reduce croup severity by 50%, decrease hospital admissions by 80%, and shorten length of stay by 12 hours.

For moderate to severe croup (Westley score 3 or above), I would also administer nebulised adrenaline. The dose is 0.5 mL/kg of 1:1000 adrenaline, with a maximum of 5 mL, diluted in 3-5 mL normal saline and given via face mask with oxygen. Adrenaline acts as an alpha-1 agonist causing vasoconstriction of the subglottic mucosa, reducing oedema within 5-15 minutes. However, the effect is temporary, lasting only 2-4 hours, so observation is required to monitor for rebound worsening."

Examiner: "What are the dosing details for dexamethasone and adrenaline?"

Candidate: "For dexamethasone, I give 0.15-0.6 mg/kg orally, IM, or IV as a single dose. The maximum dose is 10 mg regardless of weight. Oral dexamethasone syrup is 2 mg/5 mL. If the child is vomiting, I would give it IM in the lateral thigh. If critically ill, I would give it IV. I don't routinely give repeat doses, but consider it if symptoms recur after 24-48 hours.

For adrenaline, I use 0.5 mL/kg of 1:1000 solution, which is equivalent to 0.5 mg/kg adrenaline. The maximum dose is 5 mL. For a 10 kg child, that would be 5 mL of 1:1000 adrenaline. I dilute this in 3-5 mL normal saline and administer via face mask with oxygen at 6-8 L/min. The effect occurs within 5-15 minutes and lasts 2-4 hours. I would observe the child for at least 2-4 hours after adrenaline to watch for rebound worsening."

Examiner: "What is the evidence base for corticosteroids and adrenaline in croup?"

Candidate: "Corticosteroids are supported by a 2018 Cochrane review by Russell et al. which included 43 trials and over 4,500 children. This meta-analysis showed that corticosteroids significantly improved croup scores at 6 and 12 hours, reduced the rate of return visits or hospitalisations by 80%, and shortened length of stay by 12 hours. The review found that low dose dexamethasone (0.15 mg/kg) is as effective as high dose (0.6 mg/kg), and oral dexamethasone is as effective as intramuscular or intravenous.

Nebulised adrenaline is supported by a 2013 Cochrane review by Bjornson et al. which included 8 trials and over 200 children. This showed that adrenaline significantly improved croup scores within 30 minutes, but the effect is temporary and does not alter the natural history or total length of stay. The review also noted that there is no evidence of a difference between L-adrenaline and racemic adrenaline, so standard L-adrenaline is recommended.

Mist or humidified air is not recommended. A 2011 Cochrane review by Moore et al. found no evidence that humidified air provides any clinical benefit in the management of croup."

Examiner: "What are the adverse effects and contraindications for these medications?"

Candidate: "For corticosteroids, adverse effects are rare with short-term use. They may cause transient hyperglycaemia in diabetic patients, mood changes or agitation, and rarely hypertension. Contraindications are relative and should be weighed against the benefit in acute croup. I would use clinical judgment in children with uncontrolled diabetes, severe hypertension, or active infection.

For adrenaline, adverse effects include tachycardia, palpitations, tremor, and agitation. Hypertension and hypokalaemia are rare. There are no absolute contraindications in the emergency setting for a child with moderate to severe croup. Relative contraindications include severe cardiac arrhythmias and uncontrolled hypertension. I would weigh these against the risk of airway obstruction."

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Viva 3: Disposition and Follow-up

Examiner: "How do you decide who to admit and who to discharge?"

Candidate: "I would base my decision on the Westley Croup Score after initial treatment, the response to adrenaline, and social factors. For discharge, I require the Westley score to be 2 or below, no stridor at rest, normal oxygen saturation above 94% in room air, good oral intake, reliable caregivers with transport, and the patient must have received corticosteroids.

For admission, absolute indications include persistent stridor at rest after two doses of adrenaline, Westley score 3 or above at 2-4 hours after treatment, oxygen requirement, severe respiratory distress (Westley 8 or above), altered level of consciousness, rebound worsening after adrenaline, or requiring more than two doses of adrenaline within 24 hours. Relative indications include age below 6 months, underlying comorbidities like chronic lung disease or congenital heart disease, and social factors like distance from hospital, inadequate transport, parental anxiety, or non-English speaking caregivers.

I would use a lower threshold for admission for Indigenous children due to higher rates of severe disease and social determinants affecting outcomes. In remote settings, I would also have a lower threshold for admission and earlier activation of retrieval services."

Examiner: "What parental education do you provide at discharge?"

Candidate: "I would explain the expected course to parents: symptoms should improve within 6-12 hours of steroids, but cough and hoarseness may persist for 7-10 days. Noisy breathing may recur on subsequent nights, typically for 2-3 nights. I would give home care instructions: encourage oral fluids, maintain a humidified environment using a cool mist humidifier, and give paracetamol or ibuprofen for fever and discomfort.

Most importantly, I would teach them the red flags that require immediate return: stridor at rest, difficulty breathing with fast breathing or retractions, blue or pale colour, difficulty swallowing or drooling, high fever above 39°C, lethargy or difficulty waking, and no improvement or worsening after 24 hours.

I would arrange follow-up with their GP in 24-48 hours and ensure they have clear instructions about when to return to ED. I would provide written instructions and visual aids to reinforce the verbal teaching."

Examiner: "What are your concerns about a child who returns within 24 hours?"

Candidate: "A child returning within 24 hours is concerning for several reasons. First, it may indicate that the initial diagnosis was incorrect - conditions like bacterial tracheitis, epiglottitis, or foreign body aspiration may present with similar symptoms but have a different trajectory. I would reassess the child thoroughly, looking for high fever, toxic appearance, thick secretions, drooling, or muffled voice. I would also consider imaging if not previously done.

Second, it may indicate poor response to corticosteroids, which is unusual and should prompt consideration of alternative diagnoses or complications. I would check for signs of bacterial superinfection like purulent secretions, high fever, or hypoxaemia.

Third, social factors may be contributing - unreliable caregivers, inability to give medications, or lack of transport. I would assess the home environment and consider admission for observation.

Finally, it may indicate recurrent croup, which is defined as three or more episodes. This requires evaluation for underlying causes like subglottic stenosis, vascular rings, or gastro-oesophageal reflux disease."

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Viva 4: Special Populations and Complications

Examiner: "How would you manage croup in an Aboriginal child presenting to a remote health service?"

Candidate: "I would approach this case with consideration of the health disparities experienced by Aboriginal and Torres Strait Islander children, who have 2-3x higher rates of hospitalisation for croup. I would have a lower threshold for admission, considering Westley score 2-3 instead of 3-4, due to higher risk of severe disease and delayed presentation.

I would give dexamethasone immediately, even before observation, to maximise benefit. If moderate to severe (Westley 3 or above), I would also give adrenaline. I would extend the observation period to 4-6 hours instead of 2-4 hours, with reassessment every 30 minutes.

I would involve the Aboriginal Health Worker if available and ensure family-centred care. I would include extended family in decision-making, use culturally appropriate communication, and respect traditional healing practices. I would ensure clear discharge planning with reliable transport and follow-up, considering the challenges of distance and access.

If the child requires admission to hospital, I would activate the retrieval service early (within 1-2 hours of presentation) rather than waiting for deterioration, given the longer transport times. I would also consider cultural needs during transport, such as family accompaniment."

Examiner: "What are the complications of croup and how do you recognise them?"

Candidate: "Complications of croup include respiratory failure, pneumonia, bacterial tracheitis, pneumothorax or pneumomediastinum, and cardiac compromise.

Respiratory failure presents with hypoxaemia (oxygen saturation below 90%), hypercapnia (PaCO2 above 50 mmHg), respiratory acidosis (pH below 7.30), altered consciousness, or apnoea. I would recognise this by worsening work of breathing, fatigue, decreasing level of consciousness, or abnormal blood gases.

Pneumonia presents with high fever, hypoxaemia, crackles on auscultation, and consolidation on chest X-ray. I would suspect this if fever is above 39°C or symptoms worsen after initial improvement.

Bacterial tracheitis is a serious superinfection characterised by high fever, toxic appearance, copious thick purulent secretions, and lack of response to standard croup treatment. I would recognise it by high fever, thick secretions, rapidly progressive symptoms, and toxic appearance.

Pneumothorax or pneumomediastinum may occur from increased intrathoracic pressure with forceful coughing. I would recognise pneumothorax by sudden respiratory deterioration, decreased breath sounds unilaterally, and hyperresonance on percussion.

Cardiac compromise may occur from hypoxaemia causing bradycardia, or from increased work of breathing causing tachycardia and strain. I would recognise this by abnormal heart rate, arrhythmias, or hypotension."

Examiner: "When would you consider intubation and how would you prepare?"

Candidate: "I would consider intubation for respiratory failure with hypoxaemia despite supplemental oxygen or HFNC, hypercapnia with acidosis, altered level of consciousness, complete airway obstruction, or cardiac arrest. I would also consider early intubation if I anticipate rapid deterioration or cannot manage the airway with non-invasive means.

I would prepare by assembling a team including a paediatric intensivist, anaesthetist, ENT surgeon, and PICU team. I would select an endotracheal tube 0.5 to 1 mm smaller than age-based size to accommodate the oedema. For a 2-year-old, the usual tube is 4.5 mm, so I would have a 4.0 mm tube ready. I would prepare medications: ketamine 1-2 mg/kg for induction, rocuronium 1 mg/kg for paralysis after the airway is secured.

I would explain the plan to the family and obtain consent. I would confirm that capnography is available for tube confirmation. I would have suction ready for thick secretions. I would ensure the PICU bed is prepared and the retrieval team is aware if transfer is needed.

My induction strategy would preserve spontaneous respiration as long as possible, using ketamine or inhalational sevoflurane. I would place the tube under direct laryngoscopy, confirm placement with capnography and chest rise, and then ventilate with low tidal volumes and adequate PEEP. I would maintain sedation with midazolam and morphine infusions."

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OSCE Stations

OSCE Station 1: Paediatric Airway Assessment and Management

Station: Resuscitation Station (11 minutes)

Scenario: A 20-month-old child presents to your ED with a 12-hour history of barking cough and noisy breathing. The child has a temperature of 38.2°C, respiratory rate 45/minute, heart rate 140/minute, and oxygen saturation 95% on room air. On examination, you hear an inspiratory stridor at rest, mild intercostal retractions, and good air entry bilaterally. The child is alert, sitting upright on the mother's lap, and appears uncomfortable but consolable.

Task:

1. Assess the child and determine the severity
2. Calculate the Westley Croup Score
3. Initiate appropriate management
4. Determine the disposition plan

Marking Criteria:

Critical Actions (Must Pass):

• Calculates Westley score correctly (3 points)
• Orders dexamethasone
• Orders nebulised adrenaline
• Plans observation period
• Provides parental education

Common Pitfalls:

• Forgetting corticosteroids
• Using inappropriate adrenaline dose or concentration
• Discharging too early after adrenaline
• Not reassuring parents
• Missing red flags

Total Marks: 16 marks (Pass: 11/16)

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OSCE Station 2: Communication and Parental Education

Station: Communication Station (11 minutes)

Scenario: You have just assessed a 3-year-old child with croup and administered dexamethasone and nebulised adrenaline. The child's Westley score has improved from 5 to 2 after 2 hours of observation. The parents are anxious about taking their child home because they live 90 minutes away from the hospital and are worried about what to watch for.

Task:

1. Explain the diagnosis and treatment to the parents
2. Provide clear discharge instructions
3. Teach the red flags requiring immediate return
4. Address their concerns about distance

Actor Briefing (Parents):

• You are worried about your child's breathing
• You don't have much experience with sick children
• You live on a farm 90 minutes from the nearest hospital
• You want to know exactly what to watch for
• You are asking if you need to keep your child in hospital overnight

Marking Criteria:

Critical Actions (Must Pass):

• Explains diagnosis clearly
• Lists all red flags
• Provides written instructions
• Addresses distance concerns
• Checks understanding

Common Pitfalls:

• Using medical jargon
• Not acknowledging parental anxiety
• Forgetting to address distance concerns
• Not providing written materials
• Not checking understanding

Total Marks: 20 marks (Pass: 14/20)

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OSCE Station 3: Assessment and Escalation

Station: Combined Assessment/Management Station (11 minutes)

Scenario: A 4-year-old child presents with a 24-hour history of barking cough. The child received dexamethasone from the GP 6 hours ago but is now worse. On examination: temperature 39.5°C, respiratory rate 55/minute, heart rate 155/minute, oxygen saturation 90% on room air. You hear biphasic stridor, severe retractions, and decreased air entry bilaterally. The child is lethargic and difficult to arouse.

Task:

1. Assess the child's severity
2. Calculate the Westley Croup Score
3. Identify red flags
4. Initiate appropriate management and escalation

Marking Criteria:

Critical Actions (Must Pass):

• Recognises impending respiratory failure (Westley ≥12)
• Activates emergency response immediately
• Recognises red flags suggesting alternative diagnosis
• Prepares for intubation
• Calls for senior/paediatric support

Common Pitfalls:

• Missing lethargy as red flag
• Not activating emergency response
• Not considering bacterial superinfection
• Dismissing high fever
• Inadequate preparation for deterioration

Total Marks: 20 marks (Pass: 14/20)

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SAQ Practice

SAQ 1: Westley Score and Management

Question (10 marks): A 3-year-old presents with croup. On assessment: stridor present at rest, moderate retractions (obvious intercostal and subcostal), air entry decreased, no cyanosis, child is alert and appropriate.

a) Calculate the Westley Croup Score and classify severity. (3 marks) b) What is your immediate management plan? (4 marks) c) What are your discharge criteria? (3 marks)

Model Answer:

a) Westley Croup Score:

• Stridor at rest: 2 points
• Moderate retractions: 2 points
• Decreased air entry: 1 point
• No cyanosis: 0 points
• Normal consciousness: 0 points
• Total: 5 points (1 mark)
• Classification: Moderate croup (1 mark)

b) Immediate Management:

• Dexamethasone 0.15-0.6 mg/kg orally/IM/IV (single dose) (1 mark)
• Nebulised adrenaline 0.5 mL/kg of 1:1000 solution (max 5 mL) diluted in 3-5 mL normal saline via face mask with oxygen (1 mark)
• Allow parental presence and upright positioning on parent's lap (1 mark)
• Observe for 2-4 hours after adrenaline to monitor for rebound worsening (1 mark)
• Reassess Westley score at 30, 60, 120, and 240 minutes (additional point if mentioned)

c) Discharge Criteria:

• Westley score ≤2 after 2-4 hours observation (1 mark)
• No stridor at rest (1 mark)
• Normal oxygen saturation above 94% on room air, good oral intake, reliable caregivers with transport, received corticosteroids (1 mark for at least 2 additional criteria)

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SAQ 2: Differential Diagnosis

Question (8 marks): A 5-year-old presents with sudden onset of stridor and difficulty breathing. There is no preceding upper respiratory symptoms. Temperature is 38.8°C.

a) List your differential diagnosis. (4 marks) b) What clinical features would help distinguish between these conditions? (4 marks)

Model Answer:

a) Differential Diagnosis (8 marks available, award 1 mark each up to 4):

• Foreign body aspiration (1 mark)
• Bacterial tracheitis (1 mark)
• Acute epiglottitis (1 mark)
• Retropharyngeal abscess (1 mark)
• Angio-oedema (1 mark)
• Subglottic stenosis (1 mark)
• Vocal cord dysfunction (1 mark)

b) Distinguishing Features:

Foreign Body Aspiration:

• Sudden onset without prodrome (0.5 mark)
• History of choking episode (0.5 mark)
• Unilaterally decreased breath sounds (0.5 mark)
• No fever initially (0.5 mark)

Bacterial Tracheitis:

• High fever (above 39°C) (0.5 mark)
• Toxic appearance (0.5 mark)
• Copious thick purulent secretions (0.5 mark)
• Progressive symptoms despite croup treatment (0.5 mark)

Acute Epiglottitis:

• High fever, toxic appearance (0.5 mark)
• Drooling, tripod posture (0.5 mark)
• Muffled voice (0.5 mark)
• Odynophagia, difficulty swallowing secretions (0.5 mark)

Retropharyngeal Abscess:

• Neck stiffness (0.5 mark)
• Dysphagia (0.5 mark)
• Cervical lymphadenopathy (0.5 mark)
• Limited neck extension (0.5 mark)

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SAQ 3: Management and Evidence

Question (10 marks): a) What is the evidence base for corticosteroids in croup? (4 marks) b) What is the evidence base for nebulised adrenaline in croup? (3 marks) c) What therapy has NO evidence of benefit in croup? (1 mark) d) What are the dosing regimens for dexamethasone and adrenaline? (2 marks)

Model Answer:

a) Evidence for Corticosteroids:

• Cochrane review (Russell et al., 2018) includes 43 trials, over 4,500 children (1 mark)
• Significantly improves croup scores at 6 and 12 hours (1 mark)
• Reduces hospitalisations by 80% (1 mark)
• Shortens length of stay by 12 hours (1 mark)
• Low dose (0.15 mg/kg) as effective as high dose (0.6 mg/kg)
• Oral route as effective as IM/IV

b) Evidence for Nebulised Adrenaline:

• Cochrane review (Bjornson et al., 2013) includes 8 trials, over 200 children (1 mark)
• Significantly improves croup scores within 30 minutes (1 mark)
• Effect is temporary (2-4 hours) and does not alter natural history (1 mark)
• No difference between L-adrenaline and racemic adrenaline

c) No Evidence of Benefit:

• Mist or humidified air (1 mark) - Cochrane review (Moore et al., 2011)
• Steam therapy
• Decongestants/expectorants

d) Dosing Regimens:

• Dexamethasone: 0.15-0.6 mg/kg oral/IM/IV as single dose, maximum 10 mg (1 mark)
• Adrenaline: 0.5 mL/kg of 1:1000 solution nebulised, maximum 5 mL (1 mark)

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SAQ 4: Indigenous Health and Remote Practice

Question (10 marks): You are working in a remote community health service. An Aboriginal 2-year-old presents with croup. The Westley score is 4 (moderate). The family lives 2 hours drive from the hospital.

a) What are the health disparities for Aboriginal and Torres Strait Islander children with croup? (3 marks) b) How would your management differ from an urban setting? (3 marks) c) What culturally safe communication strategies would you use? (2 marks) d) When would you activate the retrieval service? (2 marks)

Model Answer:

a) Health Disparities:

• Aboriginal and Torres Strait Islander children have 2-3x higher hospitalisation rates (1 mark)
• Higher proportion require ICU admission and mechanical ventilation (1 mark)
• Longer length of stay (3-4 days vs 2 days) (1 mark)
• Contributing factors: higher tobacco smoke exposure, crowded housing, delayed presentation, comorbidities

b) Modified Management in Remote Setting:

• Give dexamethasone immediately (don't delay) (1 mark)
• Give nebulised adrenaline for moderate croup (Westley 3-4) (1 mark)
• Extend observation period to 4-6 hours (vs 2-4 hours urban) (1 mark)
• Lower threshold for admission (consider admission for Westley 2-3)
• Earlier activation of retrieval service (within 1-2 hours)
• More frequent reassessment (every 30-60 minutes)

c) Culturally Safe Communication:

• Include family and elders in decision-making (1 mark)
• Use Aboriginal Health Worker as cultural liaison if available (1 mark)
• Respect traditional healing practices
• Use simple language, avoid medical jargon
• Allow time for family consultation
• Provide written instructions in plain English

d) Retrieval Activation:

• Urgent retrieval (within 2-4 hours): Westley ≥8, oxygen requirement, altered consciousness, worsening despite treatment (1 mark)
• Planned retrieval (within 12-24 hours): Persistent moderate symptoms (Westley 3-7), multiple adrenaline doses, social factors (distance, unreliable transport) (1 mark)
• For this case with Westley 4 and 2-hour drive, I would consider planned retrieval if not improving rapidly or if social factors concern

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