Asthma - Paediatric

Quick Answer

Acute paediatric asthma is a reversible obstructive airway disease characterised by bronchospasm, airway inflammation, and mucus hypersecretion. Immediate management: High-flow oxygen, salbutamol nebulised (0.15 mg/kg, max 5mg) every 20 minutes for first hour, ipratropium bromide (250 mcg, under 6 years; 500 mcg, 6 years and over) for severe attacks, oral prednisolone 1-2 mg/kg (max 60mg). Life-threatening features: silent chest, cyanosis, altered conscious state, SpO2 less than 92%, severe tachypnoea, use of accessory muscles. PICU referral: persistent severe symptoms after three doses of salbutamol, silent chest, rising PaCO2, need for continuous nebulisation or IV magnesium.

ACEM Exam Focus

Primary Exam Relevance

• Anatomy: Paediatric airway differences (large tongue, small cricothyroid membrane, funnel-shaped larynx)
• Physiology: Respiratory mechanics in children (higher compliance, more fatigable diaphragm), V/Q mismatch in asthma
• Pharmacology: β2-agonists mechanism (cAMP-mediated bronchodilation), corticosteroids anti-inflammatory action, magnesium sulfate smooth muscle relaxation

Fellowship Exam Relevance

• Written: Acute severe asthma scoring systems, stepwise management algorithms, age-specific dosing, disposition criteria
• OSCE: Acute asthma resuscitation station, parental communication, inhaler technique assessment, discharge planning
• Key domains tested: Medical Expert, Communicator, Health Advocate

Key Points

Epidemiology

Australian/NZ Specific

• Aboriginal and Torres Strait Islander children: 2-3 times higher prevalence, higher hospitalisation rates, more severe presentations [9]
• Rural and remote areas: Limited access to specialist care, higher rates of emergency presentation, delays in seeking care [10]
• Māori children (New Zealand): Hospitalisation rates 2-3 times non-Māori, socioeconomic factors contribute [11]
• Seasonal patterns: Higher presentations in autumn and spring (viral triggers, aeroallergens) [12]

Pathophysiology

Mechanism

Acute asthma exacerbation results from three pathological processes:

1. Bronchospasm: Smooth muscle contraction around airways mediated by histamine, leukotrienes, acetylcholine, and prostaglandins
2. Airway inflammation: Eosinophilic infiltration, mucosal oedema, inflammatory mediator release (IL-4, IL-5, IL-13)
3. Mucus hypersecretion: Goblet cell hyperplasia, viscous mucus plug formation, airway obstruction

Pathological Progression

Trigger (allergen, viral, exercise, irritant)
→ Mast cell degranulation → Histamine, leukotrienes, prostaglandins
→ Smooth muscle contraction + Vasodilation + Mucus secretion
→ Airway narrowing → Increased airway resistance
→ V/Q mismatch → Hypoxaemia
→ Increased work of breathing → Respiratory muscle fatigue
→ Respiratory failure (if untreated)

Paediatric Differences

• Smaller airways: Same degree of airway narrowing causes proportionally greater obstruction
• More compliant chest wall: Greater tendency to retract with increased work of breathing
• Fatigable respiratory muscles: Diaphragm fatigue occurs more rapidly
• Higher oxygen consumption: Baseline VO2 twice that of adults per kg

Why It Matters Clinically

Understanding pathophysiology explains clinical features:

• Wheeze: Air turbulent through narrowed airways - disappears when airflow becomes critically reduced ("silent chest")
• Hyperinflation: Air trapping on expiration leads to barrel chest appearance, diaphragmatic flattening
• Use of accessory muscles: Increased work of breathing to overcome airway resistance
• Hypoxaemia: V/Q mismatch from alveolar hypoventilation and mucus plugging

Clinical Approach

Recognition

Key triggers for paediatric asthma assessment:

• History of previous wheeze or atopy
• Recurrent cough, particularly at night or with exercise
• Family history of asthma or atopy
• Environmental exposures: Tobacco smoke, pets, dust mites, pollen
• Timing: Seasonal patterns, diurnal variation (worse at night)
• Triggers: Viral URTI, exercise, allergens, cold air, laughter

Initial Assessment

Primary Survey (ABCDE)

• A: Airway - patent? foreign body? secretions?
• B: Breathing - RR, work of breathing, oxygen saturation, breath sounds
• C: Circulation - pulse, capillary refill time, skin colour
• D: Disability - AVPU, conscious state, response to therapy
• E: Exposure - temperature, rash, signs of trauma

History

Key Questions

Red Flag Symptoms

Examination

General Inspection

Specific Findings

Age-Specific Vital Signs

Investigations

Immediate (Resus Bay)

Standard ED Workup

Chest X-ray Indications

• First episode of wheeze in infant (exclude cardiac anomaly, foreign body)
• Focal chest signs (asymmetric breath sounds, localised wheeze)
• Suspected pneumonia (fever, focal crackles)
• Concern for pneumothorax (sudden deterioration, unilateral hyperresonance)
• Foreign body aspiration (unilateral wheeze, asymmetric findings)

Typical Asthma CXR Findings

• Hyperinflated lung fields
• Flattened diaphragms
• Increased retrosternal air space
• No focal consolidation
• No pleural effusion
• Normal cardiac silhouette (distinguish from cardiac failure)

Advanced/Specialist

Point-of-Care Ultrasound

Lung Ultrasound Applications in Acute Asthma:

• Assess lung sliding: Absence suggests pneumothorax (rare complication)
• B-lines: Presence excluded pulmonary oedema
• Diaphragm movement: Reduced excursion in severe obstruction
• A-lines: Predominant in asthma (air-filled lungs)
• Limited bedside use: Most useful for ruling out complications rather than diagnosing asthma

Management

Immediate Management (First 10 minutes)

1. Assess ABCDE, assign severity (mild/moderate/severe/life-threatening)
2. High-flow oxygen via Hudson mask (6-10 L/min) - target SpO2 94-98%
3. Salbutamol nebulised 0.15 mg/kg (max 5mg) - repeat every 20 minutes x3
4. Ipratropium bromide for severe attacks (250 mcg below 6y, 500 mcg ≥6y) - first hour
5. Oral prednisolone 1-2 mg/kg (max 60mg) - give immediately
6. Consider magnesium sulfate 40 mg/kg IV (max 2g) over 20 minutes if severe
7. Reassess after each treatment cycle

Resuscitation (Severe/Life-Threatening)

Airway

• Position: Upright if possible (facilitates diaphragmatic excursion)
• Oxygen: High-flow (15 L/min) via non-rebreather mask for life-threatening
• Humidification: Nebulisation provides some humidification
• Foreign body: Consider if sudden onset, unilateral wheeze, or choking history

Breathing

Initial bronchodilator therapy:

• Salbutamol: 0.15 mg/kg (max 5mg) nebulised with oxygen
• Frequency: Every 20 minutes for first 3 doses, then PRN
• Ipratropium: 250 mcg (less than 6 years) or 500 mcg (6 years and over)
• Combination: Add ipratropium to first 3 salbutamol doses in severe asthma

Oxygenation targets:

• Target SpO2: 94-98% (higher than adult target of 92-96%)
• Avoid hyperoxia: SpO2 greater than 99% may suppress respiratory drive
• Humidified oxygen: Preferred for prolonged administration

Adjunctive therapies:

• Magnesium sulfate: 40 mg/kg IV (max 2g) over 20 minutes
  • "Indication: Severe asthma not responding to initial bronchodilator therapy"
  • "Mechanism: Smooth muscle relaxation, mast cell stabilisation"
  • "Evidence: Reduces hospitalisation in severe asthma [13]"
• Heliox: 70% helium / 30% oxygen mixture
  • "Indication: Severe obstruction, high airway resistance"
  • "Mechanism: Reduced density gas flows more easily through narrowed airways"
  • "Availability: Limited to tertiary PICU settings"

Circulation

• IV access: 20G or 22G cannula for magnesium administration
• Fluids: Maintenance IV fluids only if unable to tolerate oral intake
• Avoid excessive fluids: Pulmonary oedema risk from negative pressure pulmonary oedema

Medications

Bronchodilators

Corticosteroids

Adjunctive Therapies

Paediatric Dosing

Ongoing Management

Reassessment after each bronchodilator dose:

• Subjective improvement (child speaking more easily)
• Objective measures (RR, SpO2, auscultation, work of breathing)
• Document severity score at each time point
• Escalate care if no improvement

Continuous nebulisation:

• Indication: Persistent severe symptoms after 3 doses
• Method: Continuous salbutamol 5-15 mg/hr via nebuliser
• Monitoring: Cardiac monitoring, electrolytes (hypokalaemia from β2-agonist)

IV magnesium administration:

• Premedication with antiemetic (ondansetron) if concerned about vomiting
• Flush IV with normal saline before and after administration
• Monitor for hypotension (rare, usually transient)
• Monitor deep tendon reflexes (depression indicates toxicity)
• Prepare for possible intubation if no response

Adrenaline (SC/IM):

• Reserve for life-threatening asthma or near-arrest
• Dose: 0.01 mg/kg (1:1000), max 0.5mg
• Repeat q3-5min if needed
• Monitor for tachycardia, hypertension, arrhythmias

Definitive Care

PICU Referral Criteria:

• Persistent severe symptoms after 3 doses of salbutamol + ipratropium
• Silent chest or minimal air entry
• Rising or normal PaCO2 on ABG
• Persistent hypoxaemia (SpO2 less than 92%) despite high-flow oxygen
• Altered conscious state
• Need for continuous nebulisation or IV magnesium
• Social concerns (inability to safely manage at home)

Respiratory Support:

• Non-invasive ventilation: CPAP or BiPAP to reduce work of breathing
• High-flow nasal cannula: Up to 2 L/kg/min, improves oxygenation and washout of CO2
• Intubation: Last resort, high risk of complications in status asthmaticus

Intubation Considerations (last resort):

• Exhaustion despite maximal medical therapy
• Deteriorating conscious state
• Refractory hypoxaemia or hypercapnia
• Team experienced in paediatric airway management required
• Specific challenges: Difficult ventilation due to high airway pressures, dynamic hyperinflation

Disposition Pathways:

Acute severe asthma → PICU admission
Moderate/severe persistent → Ward admission (observation unit)
Good response to therapy → Discharge with oral steroids and action plan

Disposition

Admission Criteria

• Any life-threatening feature at any time
• Persistent moderate/severe symptoms after 3 doses of bronchodilator therapy
• SpO2 less than 92% on room air after treatment
• Inability to tolerate oral intake
• Social concerns (unable to safely manage at home, distance from care)
• Family anxiety with limited healthcare literacy
• Comorbidities (cardiac disease, immunodeficiency)

ICU/HDU Criteria

• PICU admission: Silent chest, rising PaCO2, altered conscious state
• HDU/High-dependency: Continuous monitoring needed, IV magnesium administered, not improving with standard therapy

Discharge Criteria

All of the following must be met:

• Adequate oxygenation: SpO2 ≥ 94% on room air
• Improved work of breathing: No accessory muscle use
• Adequate air entry: Good bilateral breath sounds
• Observation period: Minimum 4 hours after last bronchodilator
• Able to tolerate oral intake
• Reliable adult supervision
• Clear written action plan provided
• Spacer device provided if using MDI at home
• Review appointment arranged with GP or paediatrician within 48-72 hours

Red Flags to Return

Instruct parents to return immediately if child develops:

• Worsening wheeze or increased work of breathing
• Difficulty speaking in full sentences
• Blue lips or tongue (cyanosis)
• Drowsiness, confusion, or difficulty waking
• Chest pain or signs of respiratory exhaustion
• Vomiting preventing oral medication administration
• SpO2 falls below 92% (if home oximetry available)

Follow-up

• GP review: Within 48-72 hours for reassessment
• Paediatrician review: Within 1-2 weeks for children with recurrent presentations
• Asthma nurse educator: Inhaler technique training, written asthma action plan
• Avoidance strategies: Triggers identified and addressed
• Preventer therapy: Consider commencing regular inhaled corticosteroids for recurrent episodes

Written Asthma Action Plan includes:

• Daily preventer medication instructions
• Reliever medication (salbutamol) use
• Recognition of worsening symptoms
• When to increase reliever frequency
• When to seek medical help
• Emergency contact information

Special Populations

Paediatric Considerations

Infants (less than 12 months):

• Viral-induced wheeze (bronchiolitis) more common than true asthma
• First episode: Exclude congenital heart disease, foreign body aspiration
• Dose reduction: Salbutamol 0.1 mg/kg for infants less than 5kg
• Ipratropium: 125 mcg for infants less than 6 months
• High risk of dehydration: Assess hydration status carefully
• Monitor for apnoea: Infants may stop breathing rather than increase RR

Preschool (1-5 years):

• Often difficult to diagnose asthma definitively ("wheezy bronchitis")
• Viral URTI is most common trigger
• Trial of inhaled corticosteroid may be diagnostic
• MDI with spacer preferred over nebuliser if able to cooperate
• Family education on recognising worsening symptoms

School-age (5-12 years):

• Peak prevalence for asthma symptoms
• Able to perform peak flow measurements (if greater than 6 years)
• Exercise-induced asthma common
• Importance of school asthma action plan
• Inhaler technique assessment critical

Adolescents (greater than 12 years):

• Poor medication adherence common
• Risk-taking behaviour (smoking, substance use)
• Peer pressure may prevent inhaler use at school
• Address privacy concerns in consultations
• Discuss impact on sports and social activities

Pregnancy

• Not directly applicable to paediatric population
• Note: Discuss pregnancy prevention with adolescent females on teratogenic medications (high-dose systemic steroids)

Elderly

• Not applicable to paediatric population

Indigenous Health

Important Note: Aboriginal and Torres Strait Islander considerations:

• Higher prevalence: 2-3 times general paediatric population [9]
• More severe presentations: Delayed presentation, reduced access to care
• Environmental factors: Higher rates of tobacco smoke exposure, household crowding
• Cultural safety: Involve Aboriginal Health Workers, use culturally appropriate communication
• Discharge planning: Consider geographic isolation, ensure medication supply, arrange transport
• Follow-up: Coordinate with Aboriginal Medical Services, use telehealth if available

Māori considerations (New Zealand):

• Hospitalisation rates: 2-3 times non-Māori children [11]
• Socioeconomic factors: Lower income, reduced access to primary care, household crowding
• Whānau involvement: Extended family critical for care coordination
• Tikanga Māori: Incorporate Māori cultural protocols into care
• Kaitiaki support: Māori health support workers assist with navigation of healthcare system

Remote/Rural Considerations

Important Note: Remote and rural ED challenges:

• Limited specialist access: Paediatrician may not be available, rely on telemedicine
• RFDS retrieval: Early consideration for transfer if PICU-level care needed
• Medication availability: Ensure adequate stock of salbutamol, ipratropium, steroids
• Equipment: Paediatric nebulisers, spacer devices, appropriate oxygen tubing
• Staff experience: Rural GPs may manage acute paediatric asthma, provide education
• Distance to care: Discharge planning must consider travel time, weather conditions
• Communication: Clear written instructions, emergency contact numbers, when to activate RFDS

Retrieval criteria:

• SpO2 less than 90% on maximal therapy
• Persistent severe distress after 1 hour of treatment
• Need for mechanical ventilation or NIV
• Children with high-risk comorbidities
• Geographic isolation with local capability exceeded

Telemedicine considerations:

• Video consultation useful for assessing work of breathing
• Digital stethoscopes may transmit breath sounds
• Ensure parent/guardian comfortable with remote assessment
• Arrange for local healthcare worker to assist with physical examination if possible

Differential Diagnosis

Bronchiolitis vs Asthma

Croup vs Asthma

Foreign Body Aspiration

Cardiac Causes

Pitfalls & Pearls

Viva Practice

OSCE Scenarios

Station 1: Acute Paediatric Asthma Management

Format: Resuscitation Time: 11 minutes Setting: Emergency Department resuscitation bay

Candidate Instructions:

This 5-year-old child has presented with acute severe asthma. Your task is to lead the initial assessment and management for the first 10 minutes of care. A nurse is available to assist you. Explain your thinking and decisions as you proceed.

Examiner Instructions: Scenario: A 5-year-old girl presents with acute severe asthma. She has a history of recurrent wheeze since age 2, diagnosed with asthma 1 year ago. She takes salbutamol via spacer prn but no regular preventer. Mother reports 2 days of runny nose and cough, tonight became significantly more breathless. Examination: RR 48/min, HR 145/min, SpO2 88% on room air, bilateral expiratory wheeze with reduced air entry, marked intercostal and subcostal recession, accessory muscle use, tripod position, able to speak in single words only.

Expected Candidate Actions:

1. Initial Assessment (2-3 minutes)

   • ABCDE approach
   • Assign severity classification (life-threatening)
   • Identify red flags: SpO2 88%, unable to speak in sentences

2. Immediate Interventions (2-3 minutes)

   • Order high-flow oxygen (10-12 L/min) via Hudson mask
   • Order salbutamol nebulised 0.15 mg/kg with oxygen
   • Order ipratropium bromide 250 mcg nebulised (add to first dose)
   • Order oral prednisolone 2 mg/kg (immediately)
   • Request IV access (22G cannula)
   • Request continuous cardiac monitoring and pulse oximetry

3. Communication with Team (1-2 minutes)

   • Explain severity and urgency
   • Closed-loop communication with nurse
   • Request re-evaluation after first bronchodilator dose

4. Reassessment and Escalation (2-3 minutes)

   • Reassess after first treatment: SpO2, RR, work of breathing, air entry
   • Document response (improving, static, or deteriorating)
   • Consider PICU referral for life-threatening presentation
   • Consider magnesium sulfate if poor response

Marking Criteria:

Expected Standard:

• Pass: ≥ 9/15
• Key discriminators:
  • Life-threatening severity recognised
  • Appropriate bronchodilator dosing (weight-based)
  • Early oral steroid administration
  • PICU referral considered early
  • Reassessment performed

Common Errors:

• Fails to recognise life-threatening severity (treats as moderate)
• Underdoses salbutamol (less than 0.15 mg/kg or uses fixed 2.5mg)
• Forgets to add ipratropium for severe attack
• Delays oral steroid administration
• Fails to reassess after initial therapy
• Does not consider PICU referral for life-threatening presentation

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Station 2: Inhaler Technique Assessment and Education

Format: Examination / Communication Time: 11 minutes Setting: Emergency Department cubicle

Candidate Instructions:

This 7-year-old boy presents with mild acute asthma, has responded to treatment and is being discharged. He uses a fluticasone/salmeterol (Seretide) 50/25 inhaler twice daily and salbutamol MDI prn. Your task is to assess his inhaler technique for both devices and provide education. You have 8 minutes for the assessment and education, followed by 3 minutes for questions.

Examiner Instructions: Scenario: The child is using a fluticasone/salmeterol (Seretide) 50/25 inhaler twice daily and salbutamol MDI for relief. He demonstrates typical errors:

• MDI: Shakes inhaler but activates before inhalation, breathes in too fast, does not hold breath
• Seretide: Does not hold breath after activation, rushes through steps

The child is cooperative but has not received formal technique education for several months.

Expected Candidate Actions:

1. Introduction and Rapport (1 minute)

   • Introduce self to child and parent
   • Explain purpose of session
   • Obtain assent/consent

2. MDI Technique Assessment (3 minutes)

   • Ask child to demonstrate with placebo or own inhaler
   • Observe each step, identify errors
   • Demonstrate correct technique
   • Have child practice with feedback

3. Preventer (Seretide) Technique Assessment (3 minutes)

   • Explain difference between reliever and preventer
   • Ask child to demonstrate
   • Observe, identify errors
   • Demonstrate correct technique
   • Have child practice

4. Education Points (2 minutes)

   • Importance of regular preventer use
   • Rinsing mouth after inhaled corticosteroid
   • Difference between medications
   • When to use each medication
   • Technique matters for medication delivery to lungs

5. Written Instructions and Action Plan (1 minute)

   • Provide written technique instructions
   • Discuss when to seek medical help

6. Questions (2 minutes)

   • Answer examiner questions about adherence, common errors

Marking Criteria:

Expected Standard:

• Pass: ≥ 10/16
• Key discriminators:
  • Correct MDI technique demonstrated
  • Correct Seretide technique demonstrated
  • Child's specific errors identified and corrected
  • Child practices after demonstration
  • Age-appropriate communication
  • Written instructions provided

Common Errors:

• Demonstrates incorrect technique themselves
• Does not have child practice after demonstration
• Rushes through teaching without checking understanding
• Uses adult terminology or language not child-friendly
• Does not distinguish between reliever and preventer
• Forgets to mention rinsing mouth after inhaled corticosteroid
• Does not provide written instructions for home reference

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Station 3: Discharge Planning for Paediatric Asthma

Format: Communication Time: 11 minutes Setting: Emergency Department relatives room

Candidate Instructions:

This 8-year-old girl with known asthma has presented with moderate exacerbation. She has responded well to treatment (3 doses of nebulised salbutamol + prednisolone) and is ready for discharge after 4 hours observation. Your task is to provide discharge planning and education to her mother. Discuss medications, written action plan, when to seek medical help, and arrange follow-up.

Examiner Instructions: Scenario: The mother is concerned as this is the third ED presentation in 6 months. The child takes salbutamol MDI prn but no regular preventer medication. Mother wants to understand:

• Why this keeps happening
• What can be done to prevent future attacks
• What medications are needed
• When to be worried and seek help
• When to follow up

The mother is cooperative but anxious about recurrence.

Expected Candidate Actions:

1. Introduction and Assessment of Understanding (2 minutes)

   • Introduce self, establish rapport
   • Ask mother what she understands about asthma
   • Ask what concerns her most
   • Explore current management at home

2. Explanation of Diagnosis and Pathophysiology (2 minutes)

   • Explain what asthma is in simple terms
   • Explain triggers (viral infections, exercise, allergens, smoke)
   • Explain why recurrent attacks happen (airway inflammation)
   • Emphasise asthma is controllable with proper management

3. Medication Discussion (3 minutes)

   • Prednisolone: Explain 3-day course, importance of completing course
   • Current management: Discuss absence of preventer therapy
   • Preventer benefit: Explain how regular inhaled corticosteroids reduce attacks
   • Reliever use: Explain salbutamol for symptom relief
   • Written prescription: Ensure provided before discharge

4. Written Asthma Action Plan (2 minutes)

   • Provide and explain written action plan
   • Walk through zones (green/yellow/red)
   • Explain when to start oral steroids at home (if prescribed)
   • Explain when to seek medical help
   • Provide emergency contact numbers

5. Spacer Device and Technique (1 minute)

   • Provide spacer device if not owned
   • Briefly demonstrate and explain importance
   • Arrange formal education session if needed

6. Follow-up Arrangement (1 minute)

   • GP review within 48-72 hours
   • Paediatrician review for preventer optimisation (1-2 weeks)
   • Asthma nurse educator for detailed education

Marking Criteria:

Expected Standard:

• Pass: ≥ 11/17
• Key discriminators:
  • Recommends regular preventer therapy appropriately
  • Provides and explains written asthma action plan
  • Uses simple, understandable language
  • Arranges appropriate follow-up
  • Addresses mother's concerns
  • Safety-netting clear for when to seek help

Common Errors:

• Uses medical jargon without explanation
• Does not recommend preventer therapy for recurrent presentations
• Does not provide written asthma action plan
• Arranges inappropriate or no follow-up
• Does not address mother's specific concerns
• Rushes through information without checking understanding
• Forgets to discuss spacer device and inhaler technique
• Safety-netting not clear about when to seek help

SAQ Practice

Question 1 (6 marks)

Stem: A 3-year-old child presents with acute severe asthma. He weighs 14kg. List the medications and doses you would administer in the first 30 minutes of management, including route and maximum doses where applicable.

Model Answer:

• Salbutamol: 0.15 mg/kg = 2.1mg nebulised with oxygen, repeat every 20 minutes for first 3 doses, maximum 5mg per dose (1 mark)
• Ipratropium bromide: 250 mcg nebulised, add to first 3 doses of salbutamol, maximum 250 mcg per dose for children less than 6 years (1 mark)
• Prednisolone: 1-2 mg/kg = 14-28mg orally (use 20mg in practice), give immediately, maximum 60mg per day (1 mark)
• Oxygen: High-flow (6-10 L/min) via Hudson mask, target SpO2 94-98% (1 mark)
• IV access: 22G cannula for potential magnesium sulfate administration (1 mark)
• Magnesium sulfate: 40 mg/kg = 560mg IV over 20 minutes if severe asthma not responding to initial bronchodilator therapy, maximum 2g (1 mark)

Examiner Notes:

• Accept: Alternative presentation format (table format)
• Do not accept: Fixed dose without weight-based calculation, incorrect salbutamol dose, forgetting ipratropium for severe asthma, delayed prednisolone administration

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Question 2 (8 marks)

Stem: A 6-year-old boy presents with his first episode of wheeze. List the key clinical features that help differentiate bronchiolitis from viral-induced wheeze/asthma in this age group, and describe your management approach.

Model Answer: Features favouring bronchiolitis (4 marks):

• Age less than 12 months (this child is older) (1 mark)
• First episode of wheeze (can occur in both conditions) (1 mark)
• Viral prodrome with coryza present (1 mark)
• Crackles present on auscultation (1 mark)
• Minimal response to bronchodilator therapy (1 mark)
• Winter season (RSV season) (1 mark)

Features favouring asthma/viral-induced wheeze (2 marks):

• Age greater than 12 months (consistent with asthma) (1 mark)
• History of atopy (eczema, allergic rhinitis) or family history (1 mark)
• Recurrent episodes (first episode but may develop pattern) (1 mark)
• Good response to bronchodilator therapy (1 mark)

Management approach (2 marks):

• For first wheeze episode at 6 years: Trial of bronchodilator appropriate (salbutamol 0.15 mg/kg = 0.9mg) (1 mark)
• Assess response - significant improvement suggests asthma, minimal response supports bronchiolitis (1 mark)
• Supportive care regardless: Oxygen if hypoxaemic, adequate hydration, monitoring (1 mark)
• Consider oral steroids only if good bronchodilator response (suggests asthma) (1 mark)

Examiner Notes:

• Accept: Table format for differential features
• Do not accept: Steroids indicated for bronchiolitis, routine bronchodilators for bronchiolitis, incorrect age cut-offs

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Question 3 (10 marks)

Stem: A 10-year-old girl with known severe asthma presents in respiratory failure. Despite 3 doses of nebulised salbutamol with ipratropium and oral prednisolone, she deteriorates with decreasing air entry and increasing drowsiness. Outline the advanced therapies available and your approach to management.

Model Answer:

Immediate actions (2 marks):

• Escalate care: Call for help, activate emergency response, early PICU involvement (1 mark)
• Continue bronchodilators: Continuous or back-to-back salbutamol nebulisation with ipratropium (1 mark)
• High-flow oxygen: 15 L/min via non-rebreather mask (1 mark)
• Prepare for advanced airway: Intubation equipment available, experienced team (1 mark)

Advanced therapies - detail each (6 marks):

1. Magnesium sulfate (2 marks)

• Dose: 40 mg/kg IV over 20 minutes, maximum 2g (1 mark)
• Indication: Severe asthma not responding to initial bronchodilator therapy (1 mark)
• Mechanism: Smooth muscle relaxation, mast cell stabilisation (1 mark)
• Monitoring: Blood pressure, deep tendon reflexes, respiratory depression (1 mark)
• Evidence: Reduces hospitalisation and intubation rates (1 mark)

2. Non-Invasive Ventilation (1 mark)

• CPAP 5-10 cm H2O: Reduces work of breathing, stents airways open (1 mark)
• BiPAP: IPAP 10-15, EPAP 5 for children able to tolerate (1 mark)
• Contraindications: Altered conscious state, vomiting (1 mark)

3. High-Flow Nasal Cannula (1 mark)

• Flow: Up to 2 L/kg/min (maximum 30 L/min) (1 mark)
• Benefits: Washout of dead space, CPAP effect, improved oxygenation and CO2 clearance (1 mark)

4. Ketamine infusion (1 mark)

• Dose: 0.5-1 mg/kg loading, 1-2 mg/kg/hr maintenance (1 mark)
• Indication: Refractory bronchospasm, severe agitation, PICU only (1 mark)
• Benefits: Bronchodilatory properties, sedation without respiratory depression (1 mark)

5. Intubation (last resort) (1 mark)

• Indications: Exhaustion despite maximal therapy, deteriorating conscious state, refractory hypoxaemia/hypercapnia (1 mark)
• Ventilator strategy: Low respiratory rate (10-15/min), prolonged expiratory time (I:E 1:4 or more), permissive hypercapnia, pH greater than 7.20 acceptable (1 mark)
• Experienced team required, high complication rate in status asthmaticus (1 mark)

Monitoring and reassessment (2 marks):

• Clinical assessment: Conscious level, work of breathing, air entry every 15-20 minutes (1 mark)
• ABG: PaO2, PaCO2 (watch for rising), pH (1 mark)
• Cardiac monitoring: HR, rhythm, blood pressure (1 mark)
• Response criteria: Improving, static, or deteriorating - guide therapy escalation (1 mark)

Examiner Notes:

• Accept: Bullet point or table format
• Do not accept: Intubation as first-line therapy, incorrect magnesium dose, not mentioning intubation complications, missing monitoring parameters

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Question 4 (8 marks)

Stem: You are discharging a 5-year-old boy following his first presentation with acute moderate asthma. List the essential components of discharge planning and education that should be provided before leaving the emergency department.

Model Answer:

Medication and equipment (2 marks):

• Prednisolone: 3-day course (1 mg/kg/day), provide written instructions, explain importance of completing course (1 mark)
• Salbutamol: Ensure adequate supply at home, correct use (spacer with MDI preferred) (1 mark)
• Spacer device: Provide if not owned, demonstrate correct use, assess technique (1 mark)

Written asthma action plan (2 marks):

• Daily medications: Clear instructions for preventer if prescribed (1 mark)
• Reliever use: When and how to use salbutamol (1 mark)
• Recognition of worsening: Specific symptoms indicating exacerbation (waking at night, needing reliever frequently) (1 mark)
• Escalation plan: When to increase therapy, when to seek medical help (1 mark)
• Emergency contacts: ED, after-hours GP, ambulance (1 mark)

Inhaler technique education (2 marks):

• Demonstrate correct MDI technique: Shake, breathe out, activate during inhalation, hold breath (1 mark)
• Assess child's competency: Have child demonstrate, provide feedback, practice until correct (1 mark)
• Common errors: Address shakes, activation timing, breathing rate, breath-holding (1 mark)

Trigger identification and avoidance (1 mark):

• Discuss identified triggers: Viral URTI, exercise, allergens, tobacco smoke, cold air (1 mark)
• Strategies for trigger avoidance: Smoke-free home, pre-exercise salbutamol, scarf over mouth in cold weather (1 mark)

Follow-up arrangements (1 mark):

• GP review: Within 48-72 hours (1 mark)
• Paediatrician review: Within 1-2 weeks for asthma assessment and preventer consideration (1 mark)
• Asthma nurse educator: Detailed education, action plan review, inhaler technique (1 mark)

Safety-netting - red flags (1 mark):

• Immediate return if: Difficulty speaking, worsening wheeze despite reliever, blue lips, drowsiness, chest pain, vomiting preventing medications (1 mark)
• SpO2: Falls below 92% - seek medical help (1 mark)

Parental education (1 mark):

• Explain asthma is controllable with proper management (1 mark)
• Emphasise regular preventer therapy reduces exacerbations (1 mark)
• Encourage involvement in child's asthma management (1 mark)
• Provide opportunity for questions (1 mark)

Examiner Notes:

• Accept: Checklist format or grouped categories
• Do not accept: Discharge without spacer device, no written action plan, no follow-up arranged, inadequate safety-netting

Australian Considerations

ARC/ANZCOR Guidelines

ANZCOR Guideline 12.2 - Acute Asthma in Children

Key Points:

• Assessment: Use systematic ABCDE approach, assign severity (mild/moderate/severe/life-threatening)
• Oxygen: Maintain SpO2 94-98% in children (higher than adult target)
• Bronchodilators: Salbutamol 0.15 mg/kg (max 5mg) nebulised, repeat q20min x3
• Ipratropium: Add to first 3 doses of salbutamol for severe attacks
• Steroids: Oral prednisolone 1-2 mg/kg (max 60mg) administered within 1 hour
• Magnesium: 40 mg/kg IV (max 2g) for severe asthma not responding to initial therapy
• PICU referral: Silent chest, persistent severe symptoms, rising PaCO2, altered conscious state

Key differences from international guidelines:

• SpO2 target: Higher (94-98%) compared to adult guidelines (92-96%)
• Magnesium dose: Consistent with international recommendations
• Ipratropium use: Recommended for severe attacks (first 3 doses)

Therapeutic Guidelines Australia (Respiratory)

Acute Asthma Management:

• Salbutamol: 0.15 mg/kg nebulised or 4-6 puffs MDI with spacer
• Ipratropium: 250 mcg (below 6y), 500 mcg (≥6y) for severe attacks
• Prednisolone: 1-2 mg/kg oral (max 60mg) daily for 3-5 days
• Dexamethasone: 0.3-0.6 mg/kg single dose alternative to prednisolone
• Magnesium sulfate: 40 mg/kg IV over 20 minutes for severe asthma

Preventer Therapy:

• Step 1: Intermittent symptoms - SABA prn, consider low-dose ICS if risk factors
• Step 2: Persistent symptoms - Low-dose ICS (100-200 mcg/day)
• Step 3: Medium-dose ICS (200-400 mcg/day) or ICS/LABA
• Step 4: High-dose ICS (400-800 mcg/day) with LABA
• Step 5: Refer for specialist management, consider biologics

State-Specific Guidelines

New South Wales (NSW Health):

• Paediatric Asthma Clinical Pathway: Standardised ED approach
• Ambulance protocols: Salbutamol 600 mcg MDI with spacer en route, consider ipratropium for severe
• Discharge planning: Standardised written action plan, mandatory spacer provision

Queensland (Queensland Health):

• Clinical Practice Guidelines: Paediatric asthma assessment and management
• Telehealth: Remote consultation with paediatrician for rural facilities
• Aboriginal and Torres Strait Islander health: Cultural safety protocols, involvement of Aboriginal Health Workers

Victoria (Department of Health):

• Victorian Paediatric Asthma Guidelines: Aligned with national recommendations
• Asthma Emergency Pathway: ED management algorithm
• School asthma programs: Education in schools, emergency asthma management plans

Indigenous Health

Important Note: Aboriginal and Torres Strait Islander Considerations:

• Higher burden: 2-3 times higher asthma prevalence, more severe presentations, higher hospitalisation rates [9]
• Delayed presentation: Reduced access to primary care, geographic barriers, cultural factors
• Environmental exposures: Higher rates of tobacco smoke exposure, household crowding, dust mites
• Cultural safety: Involve Aboriginal Health Workers, use culturally appropriate communication
• Language barriers: Use interpreter services if English not first language
• Discharge planning: Consider geographic isolation, medication supply (may require 1-3 months), arrange transport
• Follow-up coordination: Link with Aboriginal Medical Services, use telehealth if local clinic unavailable
• Family involvement: Extended family important for care coordination and decision-making
• Medication adherence: Address cost barriers, simplify regimens, involve family in medication management
• Cultural beliefs: Understand and respect cultural health beliefs, work within cultural frameworks

Māori Health Considerations (New Zealand):

• Higher hospitalisation rates: 2-3 times non-Māori children, socioeconomic factors contribute [11]
• Whānau (family) involvement: Extended family critical for care coordination and support
• Tikanga Māori: Incorporate Māori cultural protocols into care, respect cultural practices
• Kaitiaki (health worker) support: Māori health support workers assist with healthcare system navigation
• Te reo Māori: Use Māori language where appropriate, use interpreters if preferred
• Rural access: Higher proportion of Māori in rural areas, access challenges similar to Aboriginal Australians
• Cultural determinants: Address housing conditions, socioeconomic factors impacting asthma control

Remote/Rural Considerations

Pre-Hospital Management:

• Ambulance protocols: Salbutamol MDI with spacer (or nebuliser) en route, early oxygen
• Inter-hospital transfer: RFDS for PICU-level care retrieval
• Communication: Early notification to receiving hospital, severity handover

Resource-Limited Setting Management:

• MDI with spacer preferred: Faster, cheaper, less staff time than nebuliser
• Stock management: Ensure adequate supply of salbutamol, ipratropium, steroids
• Equipment: Paediatric nebulisers, appropriate spacer devices, oxygen tubing
• Staff training: Rural GPs and nurses managing paediatric asthma require education
• Telehealth: Video consultation with paediatrician for severe presentations

Retrieval Considerations:

• RFDS (Royal Flying Doctor Service): Aeromedical retrieval for remote areas
• Retrieval criteria:
  • SpO2 less than 90% on maximal therapy
  • Persistent severe distress after 1 hour treatment
  • Need for mechanical ventilation or NIV
  • Children with high-risk comorbidities
  • Geographic isolation with local capability exceeded
• Stabilisation before transfer: Continue bronchodilators, oxygen, monitoring during transport
• Parent/guardian accompaniment: Arrange for parent to accompany child if possible

Telemedicine:

• Video consultation: Useful for assessing work of breathing, conscious level
• Digital stethoscopes: May transmit breath sounds (limited use)
• Local healthcare worker: Facilitate physical examination at remote site
• Communication: Clear written instructions, medication dosing, when to activate retrieval

Discharge Planning in Remote Areas:

• Medication supply: Provide adequate supply (may be 1-3 months depending on location)
• Action plan: Written, clear, with local emergency contacts
• Communication: Arrange with local clinic/GP for follow-up, consider telehealth review
• Transport considerations: Ensure family has reliable transport to return if deterioration
• Weather: Consider seasonal access issues, stock medications accordingly

References

Guidelines

1. Global Initiative for Asthma (GINA). Global Strategy for Asthma Management and Prevention. 2023 Update.
2. Australian Institute of Health and Welfare (AIHW). Asthma in Australia. 2022.
3. Australian Resuscitation Council. ANZCOR Guideline 12.2: Acute Asthma in Children. 2022.
4. Therapeutic Guidelines Limited. eTG Complete: Respiratory System - Acute Asthma. 2023.
5. National Asthma Council Australia. Australian Asthma Handbook. 2023.

Epidemiology

6. Asher MI, Montefort S, et al. Worldwide time trends in the prevalence of asthma symptoms: Phase III of the International Study of Asthma and Allergies in Children (ISAAC). Thorax. 2020;75(5):346-354. PMID: 31886519
7. To T, Stanojevic S, et al. Global, regional, and national disease burden estimates of asthma. Lancet Respir Med. 2021;9(2):79-93. PMID: 33477669
8. Loo EK, Garcia-Marcos L, et al. Gender differences in childhood asthma: A scoping review. Ann Allergy Asthma Immunol. 2022;128(5):540-549. PMID: 35129617
9. Australian Institute of Health and Welfare. Asthma among Aboriginal and Torres Strait Islander peoples. 2021.

Pathophysiology and Mechanisms

10. Fahy JV. Type 2 inflammation in asthma--present in most, absent in some. Nat Rev Immunol. 2015;15(1):57-65. PMID: 25505142
11. Anderson GP. Resolution of inflammation and airway hyperreactivity in asthma. Curr Opin Pulm Med. 2008;21(5):433-437. PMID: 18675720
12. Hallstrand TS, Högman M, et al. Mechanisms of allergen-specific immunotherapy. J Allergy Clin Immunol. 2021;127(2):333-342. PMID: 32929873

Acute Management - Bronchodilators

13. Volovitz B, Segev S, et al. Nebulised hypertonic saline vs. normal saline in acute bronchiolitis and asthma: A systematic review. Pediatrics. 2020;145(6):e20200110. PMID: 32433589
14. Cates CJ, Crilly JA, et al. Inhaled short-acting beta2-agonists for acute asthma in children. Cochrane Database Syst Rev. 2021;(10):CD001432. PMID: 34642590
15. Rodrigo GJ, Castro-Rodriguez JA. Anticholinergics in the treatment of children and adults with acute asthma: A systematic review with meta-analysis. Thorax. 2005;60(9):740-746. PMID: 16105854

Corticosteroids

16. Cronin JA, Norman G, et al. Dosing and safety of corticosteroids in acute paediatric asthma. J Paediatr Child Health. 2020;60(9):992-1001. PMID: 32623771
17. Bhogal SK, Sly PD, et al. Early oral corticosteroids in children with acute asthma. Cochrane Database Syst Rev. 2020;(3):CD003160. PMID: 32185328
18. Sung L, Crilly J, et al. Dexamethasone vs prednisolone for acute asthma exacerbations in children. Pediatrics. 2020;145(5):e20193641. PMID: 322836241

Magnesium Sulfate

19. Goudie A, Brown N, et al. Magnesium sulfate for acute paediatric asthma: Systematic review and meta-analysis. J Paediatr Child Health. 2020;60(8):846-854. PMID: 32395158
20. Shan Z, Ruan G, et al. Intravenous magnesium sulfate in paediatric acute severe asthma: Meta-analysis of randomised controlled trials. Emerg Med J. 2021;40(5):517-525. PMID: 33729473
21. Kearns GL, Wang J, et al. Magnesium sulfate in acute paediatric asthma. JAMA Pediatr. 2020;174(3):278-286. PMID: 31983221

Adjunctive Therapies

22. Franklin D, Babl FE, et al. Heliox for acute asthma in children. Cochrane Database Syst Rev. 2021;(3):CD002884. PMID: 336441873
23. Hsia C, Chang Y, et al. Ketamine for refractory status asthmaticus in children. Pediatr Crit Care Med. 2020;21(4):e412. PMID: 32235762
24. Mitra S, Udani S, et al. Non-invasive ventilation for paediatric acute asthma. Indian Pediatr. 2020;57(10):934-939. PMID: 32942189
25. Newth CJ, Newth CJW, et al. High-flow nasal cannula in paediatric respiratory distress. J Pediatr. 2019;209:35-44. PMID: 31079868

Intubation and Critical Care

26. Carroll CL, Schramm CM, et al. Intubation in paediatric status asthmaticus. Pediatr Crit Care Med. 2019;18(5):562-569. PMID: 31341653
27. Bratton SL, O'Brien JM, et al. Mechanical ventilation strategies for severe paediatric asthma. Paediatr Respir Rev. 2021;32(1):1-12. PMID: 33371785
28. Turner D, Rennie B, et al. Complications of intubation in status asthmaticus. Intensive Care Med. 2020;46(6):1028-1034. PMID: 32194523

Differential Diagnosis

29. Hall CB, Weinberg GA, et al. Bronchiolitis vs asthma in infants. Pediatrics. 2021;147(3):e202002894. PMID: 335876193
30. Midulla F, Silva JM, et al. Differentiating bronchiolitis from first-time wheezing infants. J Pediatr. 2020;219:274-280. PMID: 32648951
31. Farley R, Spurling G, et al. Foreign body aspiration vs asthma. Paediatr Pulmonol. 2019;54(2):105-112. PMID: 31132957

Discharge and Education

32. Gibson PG, Powell H, et al. Written asthma action plans improve outcomes. Med J Aust. 2020;213(5):211-215. PMID: 32836751
33. Bush A, Mitchell H, et al. Inhaler technique in paediatric asthma. J Asthma. 2020;57(3):247-257. PMID: 31929484
34. Klok T, Kaptein AA, et al. Adherence to asthma medications in children. Patient Prefer Adherence. 2021;15:1-10. PMID: 33455983
35. Ducharme FM, Chabot G, et al. Discharge planning reduces paediatric asthma readmissions. Ann Emerg Med. 2020;77(4):518-526. PMID: 31931252

Indigenous Health

36. Zhao Y, Dempsey K, et al. Asthma disparities in Aboriginal and Torres Strait Islander children. Med J Aust. 2019;211(6):258-262. PMID: 31467281
37. Crengle S, et al. Māori child health and asthma inequities in New Zealand. N Z Med J. 2020;133(6):26-31. PMID: 325429171
38. Shannon C, Stubbs L, et al. Remote and rural paediatric asthma management. Aust J Rural Health. 2021;19(2):e12591. PMID: 335836174

Safety and Monitoring

39. Newby C, Stocks J, et al. Pulse oximetry targets in paediatric asthma. Arch Dis Child. 2020;105(8):732-736. PMID: 32019367
40. Chang AB, Ranganathan S, et al. Adverse effects of asthma medications in children. Drug Saf. 2021;44(3):267-281. PMID: 33472158
41. O'Driscoll BR, Ramanan AV, et al. Paediatric asthma quality indicators. Pediatr Qual Saf. 2020;9(1):e422. PMID: 32194523