RSV Bronchiolitis: Diagnosis and Treatment
Diagnosis
Bronchiolitis is a clinical diagnosis based on history and physical examination alone—do not routinely obtain chest X-rays, viral testing, or laboratory studies 1.
Clinical Presentation
The diagnosis requires recognizing this characteristic pattern in children under 2 years of age:
- Viral upper respiratory prodrome (2-4 days): rhinorrhea, congestion, sneezing, fever
- Followed by lower respiratory tract involvement:
- Increased respiratory effort (grunting, nasal flaring, intercostal/subcostal retractions)
- Tachypnea
- Wheezing and/or crackles
- Cough
- Difficulty feeding
Key Assessment Points
Assess disease severity and risk factors systematically 1:
High-risk features requiring closer monitoring:
- Age <12 weeks (especially <3 months)
- History of prematurity
- Underlying cardiopulmonary disease (hemodynamically significant congenital heart disease, chronic lung disease/bronchopulmonary dysplasia)
- Immunodeficiency
- In utero smoke exposure
Severity indicators:
- Respiratory rate (count for full 60 seconds): 50th percentile is 41 breaths/min at 0-3 months, decreasing to 31 at 12-18 months
- Work of breathing (retractions, accessory muscle use)
- Oxygen saturation
- Hydration status and feeding ability
- Mental status changes
When Testing May Be Considered
Viral testing and radiography are not routinely recommended 1, 2. The diagnosis remains clinical. Testing may occasionally help with cohorting hospitalized patients but does not change management 2.
Treatment
Treatment is entirely supportive—there is no effective pharmacologic therapy for RSV bronchiolitis 1, 2.
What TO DO:
1. Oxygen Support
- Maintain oxygen saturation >90% 2
- Supplemental oxygen as needed
- Consider humidified high-flow nasal cannula (HHHFNC) or CPAP for severe cases requiring ICU-level care 3
2. Hydration and Nutrition
- Maintain hydration via nasogastric or intravenous routes if oral intake is inadequate 2, 4
- Monitor feeding ability closely
3. Supportive Measures
- Nasal suctioning to clear secretions
- Positioning to optimize breathing
- Serial observations (the disease course is variable and dynamic) 1
What NOT TO DO:
The following are NOT recommended (despite their continued use in some settings):
- Bronchodilators (albuterol/salbutamol): Not effective 1, 2, 4
- Epinephrine: Not recommended for routine use 2, 4
- Corticosteroids: Not beneficial 2, 4
- Nebulized hypertonic saline: Not recommended 2
- Antibiotics: Not indicated unless secondary bacterial infection is documented 2
- Chest physiotherapy: Not helpful 2
Important Caveats
One emerging exception from the most recent 2025 Australasian guideline: Combined glucocorticoids with inhaled epinephrine may have a role specifically in severe bronchiolitis requiring ICU-level care 3. However, this remains a narrow indication and does not apply to routine cases.
SARS-CoV-2 co-infection: There is new guidance suggesting glucocorticoids may have a role when COVID-19 is present concurrently 3, but this is a specific scenario.
Prevention
For high-risk infants, immunoprophylaxis is critical 4:
- Palivizumab (monoclonal antibody): Up to 5 monthly doses during RSV season
- Indications: Infants born <29 weeks' gestation, chronic lung disease of prematurity, hemodynamically significant heart disease
- New RSV prevention therapies for babies and maternal immunization are emerging 3
General prevention for all families 4:
- Hand hygiene
- Surface cleaning
- Avoiding contact with sick individuals
- Minimizing smoke exposure
Common Pitfalls to Avoid
Over-testing: Resist ordering chest X-rays and viral panels—they don't change management and increase costs 1, 2
Inappropriate medication use: Despite persistent practice patterns, bronchodilators are still prescribed by >50% of providers in some settings 5, but evidence clearly shows no benefit 2, 4
Continuous pulse oximetry: No longer required for all hospitalized patients—intermittent monitoring is sufficient for stable patients 4
Missing high-risk features: Always assess for age <12 weeks, prematurity, and cardiopulmonary disease, as these patients need closer observation 1