Bronchiolitis
NICE guideline [NG9] Bronchiolitis in children: diagnosis and management. Last updated: Aug 2021.
Background Information
Definition
A type of LRTI – particularly, with inflammation of the bronchioles – occuring in <2 y/o
Note that in those >2 y/o, usually large airways (bronchi) are affected – bronchitis.
Causes
Most commonly caused by respiratory syncytial virus (RSV)
Clinical Features
Occurs in <2 y/o:
- More common in <1 y/o
- Peak incidence at 3-6 months
Typical presentation:
- Coryzal prodrome lasting 1-3 days
- Followed by persistent cough
Examination findings:
- Fever
- Focal crackles and/or wheeze
- Poor feeding
- Respiratory distress features
- Tachypnoea
- Chest recession
- Nasal flaring
- Grunting
- Cyanosis
- Prolonged expiration phase
Young infants (esp. <6 weeks) may present atypically with apnoea and no classic signs.
Diagnosis Guidelines
Investigation and Diagnosis
Bronchiolitis should be diagnosed clinically:
NICE recommends to diagnose bronchiolitis if the baby or child has a coryzal prodrome lasting 1 to 3 days, followed by:
- persistent cough and
- either tachypnoea or chest recession (or both) and
- either wheeze or crackles on chest auscultation (or both).
NICE explicitly says NOT to routinely perform a chest X-ray (as X-ray changes may mimic pneumonia). Only consider performing a chest X-ray if intensive care is being proposed.
The following features should raise suspicion of pneumonia over bronchiolitis:
- Fever >39 °C (if present fever is typically <39 °C in bronchiolitis) and/or
- Persistent focal crackles
Viral testing for RSV detection (inc. PCR and/or antigen detection assays on respiratory samples) is available, however, not necessary to diagnose bronchiolitis.
Management Guidelines
Admission Criteria
Admission to hospital is indicated if ANY of the following:
- Apnoea
- Hypoxia
- SpO2 <90% in ≥6 weeks old
- SpO2 <92% in <6 weeks old or those with underlying health conditions
- Inadequate fluid intake (50-75% of usual volume)
- Severe respiratory distress (e.g. grunting, marked chest recession, respiratory rate >70 / min)
The following risk factors are associated with more severe bronchiolitis (these patients are more likely to require admission):
- Chronic lung disease
- Haemodynamically significant congenital heart disease
- <3 months
- Premature birth (esp. <32 weeks)
- Neuromuscular disorders
- Immunodeficiency
Management
Mainstay of bronchiolitis management is supportive care
- Respiratory support
- Oxygen therapy if SpO2 <90% (in ≥6 weeks old) or SpO2 <92% (in <6 weeks old or those with underlying health conditions)
- Initial: standard oxygen therapy via low-flow nasal cannula OR head box
- Step-up: high-flow nasal cannula
- Consider CPAP in those with impending respiratory failure
- Oxygen therapy if SpO2 <90% (in ≥6 weeks old) or SpO2 <92% (in <6 weeks old or those with underlying health conditions)
- Feeding support
- Consider nasogastric / orogastric tube or IV isotonic fluids if unable to tolerate oral fluids or insufficient intake
- Consider upper airway suction if
- Secretions are causing feeding difficulties or respiratory distress, or
- Apnoea, even with no upper airway secretions
Do not offer the following to treat bronchiolitis:
- Antibiotics
- Bronchodilators
- Corticosteroids
- Montelukast
- Hypertonic saline
- Nebulised adrenaline
Prevention
Maternal RSV vaccination
Routine RSV vaccination in pregnancy was introduced in Sep 2024 in the UK [Ref]
- All women offered RSV vaccination at 28 weeks gestation (at each pregnancy)
- Provides passive infant immunity for the first 6 months of life
Immunoprophylaxis
Involves administration of a long-acting monoclonal antibody to infants
- Approved agents in US/Europe → Palivizumab/Nirsevimab
- Summarised indications [Ref]
- All infants born during or entering their first RSV season AND/OR
- At high-risk of severe disease