6.3 Pediatric Respiratory Emergencies (Croup, Bronchiolitis, Asthma)
Key Takeaways
- Laryngotracheobronchitis (Croup) presents with barking cough, inspiratory stridor, and hoarseness; single-dose oral dexamethasone (0.6 mg/kg) is indicated for ALL severity levels (mild, moderate, severe).
- Nebulized epinephrine (epinephrine 1:1000) is indicated for moderate-to-severe croup with stridor at rest, requiring a 2-4 hour observation period post-inhalation to monitor for rebound stridor.
- Acute Bronchiolitis (most commonly RSV in infants < 2 years) is a clinical diagnosis; CPS guidelines explicitly advise AGAINST routine chest X-rays, blood gases, bronchodilators, corticosteroids, or antibiotics.
- Pediatric Asthma exacerbations are assessed using the PRAM score (Pediatric Respiratory Assessment Measure); first-line treatment includes frequent inhaled SABA (salbutamol) plus early systemic corticosteroids.
- Epiglottitis (Hib or Strep/Staph) is a pediatric airway emergency presenting with high fever, drooling, dysphagia, and tripod position; keep the child calm and secure the airway in the operating room with anesthesia/ENT.
6.3 Pediatric Respiratory Emergencies (Croup, Bronchiolitis, Asthma)
Respiratory tract emergencies represent the most frequent cause of acute pediatric hospital visits. Precise anatomical localization of airway compromise (upper vs. lower airway) and strict adherence to Canadian Paediatric Society (CPS) clinical practice guidelines are central to preventing acute respiratory failure.
Upper Airway Obstruction: Croup vs. Epiglottitis vs. Bacterial Tracheitis
Distinct clinical presentations allow rapid differentiation of acute upper airway disorders.
| Characteristic | Viral Croup (Laryngotracheobronchitis) | Acute Epiglottitis | Bacterial Tracheitis |
|---|---|---|---|
| Etiology | Parainfluenza virus (Types 1 & 3) | Haemophilus influenzae type b (Hib), S. pyogenes, S. aureus | Staphylococcus aureus, S. pneumoniae, Moraxella |
| Typical Age | 6 months to 3 years | 2 to 7 years (unvaccinated or incomplete Hib) | 1 to 8 years |
| Onset & Progression | Gradual (coryza 1–3 days, low-grade fever) | Rapidly progressive (<12 hours), toxic high fever | Subacute viral prodrome then rapid deterioration |
| Classic Symptoms | Barking cough, inspiratory stridor, hoarseness | 3 Ds: Drooling, Dysphagia, Distress (Tripod posture) | Severe stridor, copious purulent secretions, toxic appearance |
| Radiology | AP Neck: Subglottic narrowing (Steeple Sign) | Lateral Neck: Soft tissue swelling (Thumbprint Sign) | Irregular tracheal wall contours (subglottic haziness) |
| Primary Management | Dexamethasone (0.6 mg/kg) ± Nebulized Epinephrine | Airway Emergency! Secure airway in OR, IV Ceftriaxone | Secure airway in OR, tracheal suctioning, IV Vancomycin + Ceftriaxone |
Management of Croup (CPS Guidelines)
Severity is graded using the Westley Croup Score (evaluating stridor, retractions, air entry, cyanosis, and level of consciousness).
- Mild Croup (Stridor only when agitated):
- Single dose of oral Dexamethasone (0.6 mg/kg, max 16 mg). (Note: 0.15 mg/kg is equally effective if preferred).
- Discharge home with supportive care and caregiver education.
- Moderate-to-Severe Croup (Stridor at rest, intercostal/indrawing retractions, lethargy):
- Single dose of oral/IM/IV Dexamethasone (0.6 mg/kg).
- Nebulized Epinephrine: L-epinephrine 1:1000 (5 mL) or racemic epinephrine (0.5 mL of 2.25% solution in 3 mL NS). Epinephrine induces mucosal arteriole vasoconstriction, rapidly decreasing airway edema.
- Observation Mandatory: Patients receiving nebulized epinephrine must be observed in the ED for at least 2 to 4 hours. Discharge is safe only if stridor at rest has completely resolved, retractions are absent, and consciousness is normal (to ensure no rebound stridor occurs as epinephrine wears off).
Exam Trap: Never attempt to inspect the posterior pharynx with a tongue depressor in a child suspected of having Epiglottitis. Agitation can precipitate fatal complete laryngospasm. Keep the child calm in the parent's arms and transfer immediately to the operating room with Anesthesia and ENT present.
Acute Bronchiolitis
Acute bronchiolitis is a viral lower respiratory tract infection characterized by airway inflammation, edema, epithelial necrosis, and mucus plugging of small airways. It is the leading cause of hospitalization in infants < 1 year.
- Etiology: Respiratory Syncytial Virus (RSV) accounts for 75–80% of cases; human metapneumovirus, rhinovirus, and parainfluenza comprise the rest.
- Clinical Presentation: Prodrome of upper respiratory tract symptoms (rhinorrhea, low-grade fever) followed on days 3–5 by tachypnea, increased work of breathing (intercostal/subcostal retractions, nasal flaring), diffuse expiratory wheezing, and fine crackles.
CPS Clinical Practice Guidelines for Bronchiolitis
Bronchiolitis is a clinical diagnosis. The CPS guidelines explicitly mandate a minimalist, supportive approach:
- DO NOT ROUTINELY ORDER: Chest radiographs, nasopharyngeal viral swabs, blood gases, or CBC.
- DO NOT ADMINISTER:
- Corticosteroids (systemic or inhaled) — proven ineffective.
- Salbutamol / Bronchodilators — no sustained clinical benefit.
- Epinephrine (routine nebulized) — not recommended.
- Antibiotics — ineffective against viral etiology.
- Chest physiotherapy — increases infant distress without benefit.
- RECOMMENDED EVIDENCE-BASED CARE:
- Hydration: Frequent small oral feeds; if unable to maintain oral intake due to tachypnea (>60 breaths/min), initiate nasogastric (NG) or IV hydration (isotonic fluids).
- Gentle Nasal Suctioning: Superficial suctioning prior to feeds and sleep.
- Supplemental Oxygen: Administer oxygen only if SpO2 falls persistently below 90%.
Acute Pediatric Asthma Exacerbation
Asthma exacerbations involve bronchospasm, mucosal edema, and mucus hypersecretion resulting in widespread lower airway obstruction.
Pediatric Respiratory Assessment Measure (PRAM) Score
In Canadian pediatric emergency departments, severity is stratified using the PRAM score (range 0–12), assessing 5 parameters:
- Suprasternal Retractions (0 = absent, 2 = present)
- Indrawing / Intercostal Retractions (0 = absent, 1 = present, 2 = severe)
- Wheezing (0 = none, 1 = expiratory only, 2 = inspiratory & expiratory, 3 = audible without stethoscope/silent chest)
- Air Entry (0 = normal, 1 = decreased at bases, 2 = widespread decrease, 3 = severely decreased/absent)
- Oxygen Saturation (0 = ≥95%, 1 = 92–94%, 2 = <92%)
Escalation Protocol by PRAM Score
- Mild (PRAM 0–3): Inhaled Salbutamol (Ventolin) via MDI with spacer (4–8 puffs q20–30min for 1 hour). Re-evaluate.
- Moderate (PRAM 4–7): Inhaled Salbutamol (4–8 puffs q20min) + Ipratropium bromide (Atrovent, 4–8 puffs q20min for 3 doses) + Oral Dexamethasone (0.6 mg/kg) or Prednisone (1–2 mg/kg).
- Severe (PRAM 8–12 / Status Asthmaticus): Continuous nebulized Salbutamol + Ipratropium + IV Methylprednisolone + IV Magnesium Sulfate (50 mg/kg IV over 20 minutes) + Supplemental O2. Prepare for pediatric ICU admission.
Foreign Body Aspiration (FBA)
FBA occurs predominantly in children aged 1 to 3 years (peanuts, organic seeds, small toy parts).
- Presentation: Sudden onset of coughing, choking, and gagging while eating or playing, followed by localized monophonic wheeze, asymmetrical breath sounds, or persistent cough.
- Imaging: Inspiratory and expiratory chest radiographs (or bilateral decubitus films in young children). Findings include air trapping / hyperinflation of the affected side on expiration due to a ball-valve mechanism.
- Definitive Treatment: Rigid Bronchoscopy performed under general anesthesia.
A 14-month-old infant is brought to the emergency department with a 2-day history of low-grade fever, barking cough, and noisy breathing. On physical exam, the child is sitting calmly on his mother's lap with visible intercostal retractions and loud inspiratory stridor at rest. What is the most appropriate initial management sequence?
A 9-month-old infant presents to a community clinic in December with a 3-day history of clear nasal discharge, low-grade fever, tachypnea (RR 56/min), fine bilateral crackles, and widespread expiratory wheezing. SpO2 is 94% on room air. According to Canadian Paediatric Society guidelines, which of the following interventions is recommended?
A 2-year-old child eating peanuts suddenly experiences a coughing fit followed by stridor and respiratory distress. In the ED, the child is afebrile with normal vital signs except for a mild wheeze heard exclusively over the right lower lung field. Expiratory chest radiograph demonstrates focal hyperinflation of the right lung. What is the definitive management step?