πΌπ« Bronchiolitis β A monoclonal antibody to RSV (Palivizumab) is available as a monthly IM injection for high-risk preterm infants, though it is very expensive π°.
π¦ Aetiology
- Primarily caused by Respiratory Syncytial Virus (RSV), which leads to inflammation, oedema, and necrosis in the small airways β‘οΈ airway obstruction.
π Epidemiology
- Most common in infants aged 1β9 months, can affect up to 2 years.
- βοΈ Peaks in winter months (NovβMarch in the UK).
- ~30% of infants will be infected in their first year; a small proportion later develop asthma/reactive airway disease.
β οΈ Higher Risk Groups
- β€οΈ Congenital heart disease
- π¨ Chronic lung disease / Bronchopulmonary dysplasia
- π§ Neuromuscular disorders (poor airway clearance)
- π‘οΈ Immunodeficiency
- πΆ Preterm infants (immature lungs + narrow airways)
π©Ί Clinical Presentation
- Starts with coryzal symptoms π€§ (1β3 days) β‘οΈ then persistent cough.
- Other findings: pale, sweaty, tired appearance, nasal congestion, crackles + wheeze on auscultation.
- π© Respiratory distress: grunting, nasal flaring, use of accessory muscles, tachypnoea, subcostal/intercostal recession.
- Red flags: apnoeas, cyanosis, difficulty feeding, poor urine output.
π Differential Diagnoses
- Pneumonia, air leak, ARDS from sepsis
- Foreign body aspiration
- Pulmonary oedema (cardiac failure, congenital heart disease)
π§ͺ Investigations
- CXR: May show hyperinflation/patchy infiltrates, but β not routine (changes mimic pneumonia).
- Blood gas: Only if severe/worsening distress or suspected respiratory failure (esp. if FiOβ >50%).
- Virology swabs: May be used in hospital for cohorting but do not guide acute management.
π‘οΈ Prevention
- Palivizumab π: Monthly IM monoclonal antibody for high-risk infants (e.g., prematurity, congenital heart disease). Cost limits widespread use.
- Breastfeeding, smoke-free homes, and good hand hygiene reduce RSV spread.
π Management
- Home Care (mild cases):
- ποΈ Raise crib head to ease breathing.
- π‘οΈ Paracetamol for fever (>37.4Β°C); ibuprofen if >3 months.
- π§ Saline nasal drops before feeds.
- π«οΈ Humidified/steamy environment (avoid burns).
- π Nasal suction/aspirator to clear mucus.
- Hospital Referral:
- π 999 if: apnoea, severe distress (grunting, marked recession, RR >70), central cyanosis, SpOβ <92% on air.
- β‘οΈ Consider referral if: RR >60, poor feeding (<50β75% of usual intake), dehydration.
- Hospital Care:
- π§ Hydration (oral/NG/IV fluids if poor intake).
- π‘οΈ Antipyretics for fever.
- π¨ Oxygen if SpOβ persistently <92%.
- β οΈ Avoid: antibiotics, salbutamol, ipratropium, montelukast, hypertonic saline, nebulised adrenaline, corticosteroids (per NICE).
- π§΄ Gentle suctioning if upper airway secretions impair breathing.
- π¨ CPAP for impending respiratory failure.
π« Indications for Ventilation
- Progressive tachypnoea with increased work of breathing.
- Lethargy or frequent/prolonged apnoea.
- π Worsening acidosis on blood gas.
- β¬οΈ Increasing oxygen requirement despite CPAP/high-flow support.
π§βπ« Exam Tip
Bronchiolitis is usually supportive management only. A common pitfall in exams and practice is prescribing salbutamol or steroids β β they donβt work in RSV bronchiolitis! Always mention risk factors (prematurity, CHD, chronic lung disease) as they change admission thresholds.
π References
Cases β Bronchiolitis
- Case 1 β Classic presentation πΆ: A 6-month-old boy presents in December with cough, coryza, and increasing work of breathing. Exam: tachypnoea, chest recession, widespread crackles and wheeze. Oβ sats 90% on air. Diagnosis: bronchiolitis due to RSV. Managed with supportive care (oxygen, NG fluids) β no role for routine antibiotics or bronchodilators.
- Case 2 β Severe bronchiolitis π¨: A 2-month-old ex-preterm infant (born at 30 weeks) presents with apnoeas, poor feeding, and lethargy. Exam: marked subcostal recession, nasal flaring, sats 86% despite oxygen. Diagnosis: severe bronchiolitis in a high-risk infant. Managed with high-flow nasal cannula oxygen in HDU, IV fluids, and close monitoring for impending respiratory failure.
- Case 3 β Risk of dehydration π§: A 7-month-old girl presents with 4 days of cough, feeding <50% normal, and fewer wet nappies. Exam: mild recession, sats 93% on air, dry mucous membranes. Diagnosis: bronchiolitis with feeding difficulty and dehydration risk. Managed with NG feeding support, oxygen as needed, and discharge planning once feeding and oxygenation improve.
Teaching Point π©Ί: Bronchiolitis is an acute viral LRTI (usually RSV) in infants <1 year.
Features: coryza β cough, tachypnoea, recession, crackles/wheeze, poor feeding.
Admission if: Oβ sats <92%, apnoea, poor feeding/dehydration, high-risk infant (ex-preterm, heart/lung disease, immunodeficiency).
Management is supportive β oxygen, NG/IV fluids, suctioning. No routine salbutamol, steroids, or antibiotics.