Diagnosis and Treatment of Bronchiolitis
Diagnosis
Bronchiolitis is a clinical diagnosis based on history and physical examination alone—do not routinely order chest radiographs, viral testing, or laboratory studies. 1, 2, 3
Clinical Presentation
- Look for the characteristic pattern: initial upper respiratory symptoms (rhinorrhea, congestion, sneezing) followed by lower respiratory tract involvement with cough, tachypnea, wheezing, and crackles 4
- The incubation period is 4-6 days before symptoms appear 4
- Symptoms typically last 2-3 weeks, which is normal and does not indicate treatment failure 1
Physical Examination Findings
- Count respiratory rate over a full minute—tachypnea ≥70 breaths/minute indicates increased severity risk 1, 3
- Assess work of breathing by looking for nasal flaring, grunting, and intercostal/subcostal retractions 1, 3
- Listen for wheezing and crackles on auscultation 5
- Check oxygen saturation—SpO2 <90% is a key threshold for intervention 1, 2, 3
When to Consider Testing
- Approximately 25% of hospitalized infants have radiographic atelectasis or infiltrates, often misinterpreted as bacterial infection—this is why routine chest X-rays are not recommended 1
- Viral testing may have a role in reducing hospital transmission but is not needed for diagnosis 5
Risk Stratification
High-Risk Infants Requiring Closer Monitoring
- Age <12 weeks 1, 2, 3
- History of prematurity 1, 2, 3
- Hemodynamically significant congenital heart disease 1, 2, 3
- Chronic lung disease or bronchopulmonary dysplasia 1, 3
- Immunodeficiency 1, 2, 3
These infants may have abnormal baseline oxygenation and require close monitoring during oxygen weaning 1, 2
Treatment: Supportive Care Only
The American Academy of Pediatrics recommends standard oxygen delivery as the primary approach, with oxygen supplementation reserved for specific indications and avoidance of aggressive interventions. 1
Oxygen Therapy
- Administer supplemental oxygen ONLY if SpO2 persistently falls below 90% 1, 2, 3
- Maintain SpO2 at or above 90% using standard oxygen delivery methods 1, 3
- Otherwise healthy infants with SpO2 ≥90% at sea level while breathing room air gain little benefit from supplemental oxygen, particularly without respiratory distress or feeding difficulties 1, 3
- Discontinue oxygen when SpO2 is ≥90%, the infant is feeding well, and has minimal respiratory distress 1, 2, 3
- Avoid continuous pulse oximetry in stable infants—serial clinical assessments are more important than continuous monitoring 1, 2
Hydration and Feeding Management
- Assess hydration status and ability to take fluids orally 1, 2
- Infants who feed well without respiratory compromise should continue oral feeding 1, 3
- When respiratory rate exceeds 60-70 breaths per minute, feeding may be compromised and aspiration risk increases significantly—consider IV or nasogastric tube hydration at this threshold 1, 3
- Use isotonic fluids if IV hydration is needed, as infants with bronchiolitis may develop syndrome of inappropriate antidiuretic hormone (SIADH) secretion and are at risk for hyponatremia with hypotonic fluids 1, 3
Airway Clearance
- Use gentle nasal suctioning only as needed for symptomatic relief and temporary relief 1, 3
- Avoid deep suctioning—it is associated with longer hospital stays in infants 2-12 months of age 1, 3
- Do not use chest physiotherapy—it lacks evidence of benefit 1, 3, 4
What NOT to Do: Avoiding Harmful or Ineffective Interventions
Bronchodilators
Do not use bronchodilators (albuterol) routinely—they lack evidence of benefit in bronchiolitis. 1, 2, 3
- The American Academy of Pediatrics recommends against routine use, though a carefully monitored trial may be considered and should only be continued if there is a documented positive clinical response 1, 2
- This is a critical pitfall: bronchodilators are commonly overused despite clear evidence of no benefit 6
Corticosteroids
Do not use corticosteroids routinely—meta-analyses show no significant benefit in length of stay or clinical scores. 1, 2, 3
Antibiotics
Do not use antibiotics routinely—the risk of serious bacterial infection in infants with bronchiolitis is less than 1%. 1, 3
- Fever alone does not justify antibiotics 1, 3
- Use antibacterial medications only with specific indications of bacterial coinfection such as acute otitis media or documented bacterial pneumonia 1, 2, 3
Other Ineffective Therapies
- Do not use antiviral agents such as ribavirin routinely (may be considered only in highly selected situations with documented RSV and severe disease in high-risk patients) 1, 7
- Do not use chest physiotherapy 4, 8
Hospitalization Criteria
Indications for Admission
- SpO2 <90-92% 5
- Moderate-to-severe respiratory distress 5
- Dehydration or inability to maintain adequate oral intake 5
- Presence of apnea 5
- High-risk infants should be carefully assessed even with milder symptoms 5
Prevention Strategies
Pharmacological Prophylaxis
Palivizumab prophylaxis is recommended for high-risk infants, administered in 5 monthly doses (15 mg/kg IM) starting November/December. 2, 3
Non-Pharmacological Prevention
- Promote breastfeeding—breastfed infants have shorter hospital stays, less severe illness, and a 72% reduction in hospitalization risk for respiratory diseases 1, 3
- Avoid tobacco smoke exposure—it significantly increases severity and hospitalization risk 1, 3
- Limit visitor exposure during respiratory virus season to help prevent RSV transmission 1, 3
- Hand hygiene is the most important step in preventing nosocomial spread of RSV—alcohol-based disinfectants are preferred 2
Critical Clinical Pitfalls to Avoid
- Do not treat based solely on pulse oximetry readings without clinical correlation—transient desaturations can occur in healthy infants 1, 3
- Do not overlook feeding difficulties—aspiration risk increases significantly when respiratory rate exceeds 60-70 breaths/minute 1
- Do not misinterpret radiographic findings as bacterial pneumonia—atelectasis and infiltrates are common in viral bronchiolitis 1
- Continuous pulse oximetry may lead to less careful clinical monitoring in stable infants 1