How should bronchiolitis be managed in infants and young children under two years, including indications for hospitalization and supportive care?

Management of Bronchiolitis in Infants and Young Children

Bronchiolitis is managed with supportive care only—supplemental oxygen when SpO₂ persistently falls below 90% and hydration support when oral intake is inadequate—while avoiding bronchodilators, corticosteroids, antibiotics, and chest physiotherapy, which have no proven benefit. 1

Diagnosis

Bronchiolitis should be diagnosed exclusively on clinical history and physical examination without routine testing. 1 The typical presentation includes:

• Preceding upper respiratory symptoms (rhinitis, cough) followed 2–4 days later by lower airway signs: tachypnea, wheezing, crackles, nasal flaring, and use of accessory muscles 2, 1
• Do not order routine chest radiographs, viral panels, complete blood counts, or inflammatory markers—these do not alter management and may lead to unnecessary interventions 1, 3
• Reserve chest X-rays only for cases requiring intubation, unexpected clinical deterioration, or suspected underlying cardiac/pulmonary disease 1

Risk Stratification for Severe Disease

Identify high-risk infants who require closer monitoring and have higher likelihood of hospitalization:

• Age < 12 weeks (highest risk group) 1, 4, 3
• Prematurity, especially < 32 weeks gestational age 1, 4, 3
• Hemodynamically significant congenital heart disease 1, 4, 3
• Chronic lung disease of prematurity (bronchopulmonary dysplasia) 1, 3
• Immunodeficiency 1, 4, 3

Indications for Hospitalization

Admit infants who demonstrate:

• Persistent SpO₂ < 90% despite supplemental oxygen 1, 3
• Moderate to severe respiratory distress: respiratory rate ≥ 60–70 breaths/minute, significant nasal flaring, intercostal/subcostal retractions, grunting 4, 3
• Inability to maintain adequate oral intake or signs of dehydration 1, 4
• Apnea episodes 4

Supportive Care: What TO Do

Oxygen Therapy

• Administer supplemental oxygen only when SpO₂ persistently falls below 90%; maintain SpO₂ ≥ 90% 1, 3
• Otherwise healthy infants with SpO₂ ≥ 90% at sea level gain little benefit from oxygen, particularly without respiratory distress 3
• Discontinue oxygen when three criteria are met: SpO₂ ≥ 90%, adequate feeding, and minimal respiratory distress 3
• Avoid continuous pulse oximetry in stable infants—it may lead to less careful clinical monitoring and unnecessarily prolong hospitalization due to transient desaturations 3

Hydration Management

• Assess hydration status and ability to take oral fluids 1, 3
• Continue oral feeding if respiratory rate < 60 breaths/minute with minimal distress 3
• Transition to nasogastric or intravenous fluids when respiratory rate exceeds 60–70 breaths/minute—aspiration risk increases sharply at this threshold 1, 3
• Use isotonic fluids for IV hydration because infants with bronchiolitis frequently develop syndrome of inappropriate antidiuretic hormone (SIADH) secretion and are at risk for hyponatremia with hypotonic fluids 3

Airway Clearance

• Gentle nasal suctioning may provide temporary symptomatic relief for feeding and breathing 4, 3
• Avoid deep or aggressive suctioning—it is associated with longer hospital stays in infants 2–12 months of age 3

Positioning

• Elevate the head of the crib slightly to facilitate breathing 4

What NOT to Do: Interventions Without Benefit

Bronchodilators

• Do not use β-agonists routinely—they do not reduce hospital admission rates or length of stay 1, 3, 5
• A carefully monitored trial of α- or β-adrenergic agents may be attempted, but continuation is permitted only if an objective clinical response is documented 1

Corticosteroids

• Do not use systemic or inhaled corticosteroids routinely—they provide no benefit in length of stay or clinical scores 1, 3, 5

Antibiotics

• Administer antibiotics only with specific indication of bacterial co-infection (e.g., acute otitis media, documented bacterial pneumonia) 1, 3
• Fever alone does not justify antibiotics—the risk of serious bacterial infection in febrile infants with bronchiolitis is < 1% 3

Other Ineffective Interventions

• Chest physiotherapy: not recommended—does not improve outcomes 1, 3, 6
• Ribavirin: not recommended for routine use 1, 6

Clinical Course and Parental Counseling

• Bronchiolitis is self-limiting in most children 4, 6
• Symptoms (cough, congestion, wheezing) typically last 8–15 days on average 4
• 90% of infants are cough-free by day 21 4
• If cough persists > 4 weeks, consider alternative diagnoses such as protracted bacterial bronchitis 4

Prevention Strategies

General Measures

• Encourage breastfeeding—breastfed infants have 72% reduction in hospitalization risk for respiratory diseases and shorter hospital stays 3
• Avoid tobacco smoke exposure—significantly increases severity and hospitalization risk 1, 3
• Hand hygiene is the single most important measure to prevent nosocomial RSV spread; use alcohol-based hand rubs before and after patient contact 1
• Limit visitor exposure and avoid crowds during RSV season (typically November–March) 2, 3

Palivizumab Prophylaxis (High-Risk Infants Only)

• Administer monthly palivizumab (15 mg/kg IM) during RSV season (typically five doses beginning November/December) to: 1, 3
  • Infants born ≤ 28 weeks gestation during their first RSV season in the first 12 months of life
  • Infants born 29–32 weeks gestation up to 6 months of age
  • Children < 2 years with chronic lung disease requiring medical therapy within 6 months before RSV season
  • Children ≤ 24 months with hemodynamically significant congenital heart disease

Common Pitfalls to Avoid

• Do not treat based solely on pulse oximetry without clinical correlation—transient desaturations occur in healthy infants 3
• Do not continue oral feeding when respiratory rate ≥ 60–70 breaths/minute, even if SpO₂ is adequate—aspiration risk is significantly elevated 3
• Do not misinterpret radiographic findings—approximately 25% of hospitalized infants have atelectasis or infiltrates that are often mistaken for bacterial pneumonia 3
• Do not diagnose recurrent "bronchiolitis" after the first year of life—these children likely have recurrent wheezing or asthma and should not receive bronchiolitis treatment 4

Monitoring During Hospitalization

• Assess respiratory rate over a full minute—tachypnea ≥ 70 breaths/minute indicates increased severity risk 3
• Monitor work of breathing: nasal flaring, grunting, intercostal/subcostal retractions 3
• Serial clinical assessments are more important than continuous monitoring in stable infants 3
• High-risk infants (age < 12 weeks, prematurity, cardiopulmonary disease) require close monitoring during oxygen weaning 1, 3

Long-Term Considerations

• Infants hospitalized with severe bronchiolitis have increased risk of recurrent wheezing and asthma development later in childhood 2, 5
• It remains unclear whether severe viral illness causes asthma or reveals an underlying predisposition 2