Overview
Bronchiolitis is an acute viral infection of the lower respiratory tract most commonly seen in < 2-year-olds. It is generally self-limiting and management is mainly supportive.
Respiratory syncytial virus (RSV) is the most common cause.
Epidemiology
- Most common in infants <2 years with peaks at 3 and 6 months
- Most common cause of serious lower respiratory tract infection in < 1-year-olds
- Peak incidence is in the winter months
Risk Factors
Factors associated with more severe disease include:
- Prematurity
- Bronchopulmonary dysplasia
- Congenital heart disease
- Impaired airway clearance (e.g. cystic fibrosis, primary ciliary dyskinesia)
- Immunodeficiency
- Maternal smoking or passive smoke exposure
- Neuromuscular disorders
Presentation
Bronchiolitis is characterised by 1-3 days of preceding coryza (runny nose, nasal congestion, sneezing) with or without fever followed by:
Red flag features
- Apnoea
- Features of severe respiratory distress:
- Grunting
- Marked chest recession
- Respiratory rate >70 /min
- Head bobbing
- Nasal flaring
- Tracheal tugging
- Central cyanosis
- Oxygen saturations <92% when breathing air
Referral
Overview
Immediately refer to hospital by ambulance if any of the following features are present:
- Apnoea – either if seen in clinic or reported by the parent
- Infant looks seriously unwell to a healthcare professional
- Features of severe respiratory distress:
- Grunting
- Marked chest recession
- Respiratory rate >70 /min
- Central cyanosis
- Oxygen saturations <92% when breathing air
Consider a referral to hospital if any of the following apply:
- Respiratory rate >60 /min
- Difficulties with feeding or oral fluid intake (around 50-75% of the usual volume, taking into account risk factors and using clinical judgement)
- Dehydration
Investigations
All patients
- Pulse oximetry:
- To screen for hypoxia
- Viral throat swabs:
- Can identify RSV
Other investigations
Other investigations such as chest X-rays and blood tests are not routinely performed unless there is diagnostic doubt or deterioration.
If pneumonia is suspected (discussed in differential diagnoses), perform a chest x-ray.
Differential Diagnoses
Pneumonia
A diagnosis of pneumonia should be considered if any of the following apply:
- A high fever (>39°C)
- Persistently focal crackles
Asthma or viral-induced wheeze
- Persistent crackles may be present
- Recurrent episodic wheeze may be present
- Personal or family history of atopy may be present
Croup
- Patients have inspiratory stridor and a barking cough
- Symptoms are worse at night
Management
Overview
Treatment is supportive:
- Humidified oxygen is given if their oxygen saturations are:
- Persistently <90% if aged 6 weeks and older
- Persistently <92% if under 6 weeks or children of any age with underlying health conditions
- Upper airway suctioning may be considered if there is respiratory distress or feeding difficulty
- Nasogastric feeding may be considered if oral intake is insufficient
Patient Advice
- Carers should use paracetamol/ibuprofen for fevers if the child is distressed
- Carers should check on the child regularly and seek help if any deterioration occurs such as:
- Breathing rate increases or there is apnoea, cyanosis, or increased work of breathing (grunting, nasal flaring, head bobbing, marked chest recessions)
- Fluid intake 50-75% of normal
- Signs of dehydration – dry mouth or no wet nappy for 12 hours
- Child becomes less responsive or difficult to rouse
Prognosis
- Bronchiolitis is generally self-limiting and lasts for 3-7 days
- The cough may persist for up to 3 weeks