PALS Provider: Course

Management of Lower Airway Obstruction

Lower airway obstruction impairs airflow to the lungs, leading to increased work of breathing, hypoxia, and potential respiratory failure if not managed appropriately. It commonly occurs in conditions such as asthma and bronchiolitis, which narrow or block the lower airways due to inflammation, mucus production, or bronchospasm.

Key Goals of Management

  • Relieve airway obstruction by reducing inflammation and bronchospasm.
  • Improve oxygenation and ventilation to prevent respiratory failure.
  • Provide supportive care tailored to the underlying cause.

Asthma Management

Asthma is a chronic inflammatory airway disease that leads to bronchospasm, airway edema, and increased mucus production, causing reversible airflow obstruction.

Signs of Lower Airway Obstruction in Asthma:

  • Expiratory wheezing (hallmark sign)
  • Prolonged expiratory phase
  • Tachypnea and increased work of breathing (retractions, nasal flaring)
  • Coughing fits (especially at night or after exertion)
  • Severe cases: Silent chest, cyanosis, altered mental status (impending respiratory failure)

Treatment Approach for Pediatric Asthma:

Mild to Moderate Exacerbation

  • Nebulized Albuterol: 2.5 mg every 20 min as needed (or MDI + spacer)
  • Ipratropium Bromide: 500 mcg every 20 min for 3 doses
  • Systemic Corticosteroids:
    • Prednisone/Prednisolone: 1–2 mg/kg PO (max 60 mg)
    • Dexamethasone: 0.6 mg/kg PO/IV (single dose, max 16 mg)

Severe Asthma Exacerbation

  • Continuous Albuterol: 10–15 mg/hour via nebulizer
  • Magnesium Sulfate (IV): 25–50 mg/kg over 20 min (max 2 g)
  • Subcutaneous/IM Epinephrine: 0.01 mg/kg of 1:1000 (max 0.3 mg)
  • Consider BiPAP/CPAP for respiratory distress

When to Intubate: Severe fatigue, altered mental status, persistent hypoxia, or silent chest.

Key Clinical Pearls:

  • Nebulized bronchodilators and steroids are first-line
  • If worsening, escalate to magnesium or epinephrine
  • Avoid intubation unless absolutely necessary

Bronchiolitis Management

Bronchiolitis is a viral lower respiratory tract infection (commonly RSV) that leads to inflammation, mucus plugging, and airway obstruction, particularly in infants and young children.

Signs of Bronchiolitis:

  • Diffuse wheezing and crackles
  • Nasal congestion and rhinorrhea
  • Tachypnea with retractions
  • SpO₂ < 90% in severe cases
  • Apnea in high-risk infants (especially preterm or <3 months)

Mild Cases

  • Nasal suctioning
  • Hydration support
  • Monitor for worsening respiratory effort or feeding issues

Moderate to Severe Cases

  • Oxygen therapy for SpO₂ < 90%
  • High-Flow Nasal Cannula (HFNC) for moderate/severe distress
  • Trial of 3% Hypertonic Saline (select cases only)

Not Recommended

  • Albuterol or nebulized epinephrine (unless history of asthma)
  • Systemic corticosteroids
  • Antibiotics (unless bacterial co-infection suspected)

When to Intubate: Severe hypoxia despite oxygen/HFNC, apnea, or progressive fatigue.

Key Clinical Pearls:

  • Supportive care is the mainstay
  • HFNC improves ventilation in severe cases
  • Avoid unnecessary meds unless history supports it

Asthma vs. Bronchiolitis

Feature Asthma Bronchiolitis
Cause Chronic inflammation + bronchospasm Viral infection (RSV most common)
Age Group Usually >2 years old Infants <2 years old
Symptoms Recurrent wheezing, prolonged expiration, cough URI symptoms, wheezing, crackles
Treatment Bronchodilators, steroids Supportive care (oxygen, HFNC)
Response to Albuterol Yes No

Key Management Strategies

Condition First-Line Treatment Escalation Therapies
Asthma Albuterol, ipratropium, steroids Magnesium sulfate, continuous neb, epinephrine
Bronchiolitis Oxygen, suctioning, hydration HFNC, hypertonic saline (select cases)

Summary

  • Asthma = Inflammation + bronchospasm → bronchodilators & steroids
  • Bronchiolitis = Viral airway inflammation → oxygen & HFNC
  • Early recognition and tailored intervention improves outcomes

Takeaway: Lower airway obstruction can quickly lead to respiratory failure if not managed promptly. Understanding the differences between asthma and bronchiolitis ensures the right treatment approach for each condition.