Definition
Bronchiolitis is a lower respiratory tract infection that causes inflammation of the bronchioles.
Etiology- Caused by viral infection especially RSV, less commonly parainfluenza, adenovirus, rhinovirus, human metapneumovirus (hMPV)
- Typically affects children under 12 months (peak age: 6 weeks – 3 months)
- More common in winter
- Risk factors for severe disease:
- Prematurity
- Male
- Congenital heart or lung disease
- Neurological disease
- Immunodeficiency
- Age <10 weeks
- Australian Institute of Aboriginal and Torres Strait Islander background
- Maternal smoking
- Typically begins with symptoms of acute upper respiratory tract infection: cough, rhinorrhoea
- Followed by the onset of respiratory distress with fever ± tachypnoea, wheeze, widespread crackles, increase work of breathing
- Peak severity usually ~day 2-3 with resolution over 7-10 days, may have a persistent cough
- Mild cases:
- Behaviour: normal interaction and feeding
- Respiratory: normal or mild tachypnoea, no/mild chest wall retraction, SpO2 >92%, no oxygen requirement or apnoeas
- Moderate cases:
- Behaviour: some irritability, may have difficult/reduced feeding
- Respiratory: tachypnoea, moderate chest wall retraction with nasal flaring, SpO2 90-92%, may require supplemental O2 or have brief apnoeic episodes
- Severe cases:
- Behaviour: irritability, lethargy, fatigue, reluctant or unable to feed
- Respiratory: marked increase respiratory rate, marked work of breathing, SpO2 <90%, hypoxaemia may not be correctable with supplemental O2, frequent or prolonged apnoeas
- Usually a clinical diagnosis (no routine investigations)
- Chest X-ray (but would want to avoid radiation exposure to children)
- Nasopharyngeal Aspirate (NPA) for viral PCR
- Supportive therapy: minimal handling, small frequent feeds for adequate intake
- Admit children with moderate to severe disease for observation
- Consider NG at ⅔ maintenance if refusing feeds
- Supplemental O2 if SpO2 persistently <90%: nasal prongs ± humidified O2 ± Continuous positive airway pressure (CPAP)
- There is no role for antibiotics/antivirals, salbutamol, steroids or adrenaline