Acute Viral Bronchiolitis Flashcards
What is Bronchiolitis?
A viral LRT infection of the bronchioles, the smallest air passages in the lungs
What is the most common organism in Bronchiolitis?
Respiratory syncytial virus (RSV)
Which age group does Bronchiolitis most commonly affect?
Children < 2
During which season is Bronchiolitis most common?
Winter and spring
How does Bronchiolitis present?
Presents with a cough, increased work of breathing, and often affects a child’s ability to feed
In primary care, it is often confused with a common cold
Pathophysiology of Bronchiolitis
Viral infection → physiological changes:
- Proliferation of goblet cells - excess mucus production
- IgE-mediated type 1 allergic rnx - inflammation
- Bronchiolar constriction
- Infiltration of lymphocytes - submucosal oedema
- Infiltration of cytokines and chemokines
Combination of mucus, oedema and ↑ cells in bronchioles leads to:
- a ball-valve effect resulting in hyperinflation
- ↑ airway resistance
- ↑atelectasis (lung collapse)
- ↑ventilation-perfusion mismatch
Together these result in the clinical features seen in bronchiolitis
List 4 risk factors for severe Bronchiolitis
- Congenital heart disease
- NM disorders
- Immunodeficiency
- Chronic lung disease
- Prematurity
- Genetic disorders ie Trisomy 21
BUT severe illness can occur in well children
List 4 clinical features of Bronchiolitis in a history
Typical history is increasing symptoms over 2-5 days, consisting of:
- Low-grade fever
- Nasal congestion
- Rhinorrhoea
- Cough
- Feeding difficulty
List 4 clinical features of Bronchiolitis in a examination
- Tachypnoea
- Grunting
- Nasal flaring
- Intercostal, subcostal or supraclavicular recessions
- Inspiratory crackles
- Expiratory wheeze
- Hyperinflated chest
- Cyanosis or pallor
List 4 DDx for Bronchiolitis
- Pneumonia
- Croup
- Cystic fibrosis
- Heart failure - VERY IMPT not to miss this, can be difficult to diagnose
- Bronchitis
Investigations for suspected Bronchiolitis
Nasopharyngeal aspirate for Viruses, RSV and Influenza
No CXR unless specifically looking for complication ie 2o bacterial pneumonia
No blood gas unless deteriorates, then use capillary or venous rather than arterial
No bloods unless considering 2o pneumonia
When is an urgent refferal to hospital required for a child with Bronchiolitis?
- Apnoea
- Child looks seriously unwell to a healthcare professional
- Severe respiratory distress, eg. grunting, marked chest recession, or RR > 70 breaths/minute
- Central cyanosis
- Persistent O2 sats < 92% when breathing air
How would we manage a child in hospital with Acute Bornchiolitis?
- Give O2 if sats < 92% in room air
- Give fluids via nasogastric or orogastric tube if inadequate oral intake
- Consider CPAP if there is impending respiratory failure
- Perform upper airway suctioning if there are upper airway secretions or apnoea
Severe Bronchiolitis is associated with what condition?
What MUST we do to avoid this when treating?
At risk of SIADH, therefore we must restrict fluid to 66% of normal fluid intake
When can we consider discharge in a child with acute Bronchiolitis?
- Clinically stable
- Taking adequate oral fluids
- Maintaining sats > 92% for more than 4 hours
