Bronchiolitis
last authored: Feb 2010, David LaPierre
last reviewed:
Introduction
Lower resp ract infection affecting small airways, typically in children under age two. It is a leading cause of illness and hospitalization in infants and young children.
It tends to peak between 2-6 months. Boys are more comonly affected than girls.
The Case of...
a simple case introducing clincial presentation and calling for a differential diagnosis to get students thinking.
Causes and Risk Factors
Typically viral; agents vary with season:
- RSV most common November-April, with peak in January-February
- rhinovirus
Pathophysiology
Signs and Symptoms
Diagnosis is typically made clinically, with first episode wheezing in a child under two, signs of viral respiratory infection, and no other explanation.
- history
- physical exam
History
Children typically experience 1-3 days of URTI sx.
This follows by fever, cough, and mild respiratory distress.
Physical Exam
One typically sees signs of resp distress: tachypnea, intercostal/subcostal retractions, expiratory wheeze
coarse crackles
Other findings may include:
- atelectasis
- otitis media
- dehydration
Investigations
Diagnosis is clinical. Labs and imaging can rule other things out.
- lab investigations
- diagnostic imaging
Lab Investigations
CBC is not very helpful.
Arterial or capillary gases
Diagnostic Imaging
Chest X ray should be done to rule out other ominous causes. If the child is very young, very sick, or presenting atypically, imaging should strongly be considered.
Differential Diagnosis
- pneumonia
- atopy (allergic/asthma)
- chronic lung disease
- foreign body
- GERD/dysphagia
- congenital heart disease
- heart failure
Treatments
Supportive measures are key for outpatient management. These include:
- adequate fluid intake
- saline nose drops and nasal bulb suction
- trial of bronchodilators
- close follow-up
Factors suggesting severity and the need for admission include:
- poor feeding, lethargy, dehydration
- oxygen <95% on RA
- age <3months
- moderate to severe respiratory distress
- atelectasis on CXR
- parents' inability to care for child at home
Hospitalized infants should be monitored for HR and O2 sat.
Provide O2 as needed and mechanical ventilation if CO2 >55.
Fluid administration and electrolyte monitoring.
Medications
Bronchodilators should be used n the very ill.
Glucocorticoids may be trialed, but studies show inconsistent results. A subset of patients with reactive airway disease appear to benefit.
Antibiotics should not be used unless bacterial infection is clear.
Prevention
Consequences and Course
Bronchiolitis is a self-limiting illness that resolves without complications. Overall mortality is <2%.
Median duration is 12 days.
Comorbid bacterial infections are possible but uncommon.
Additional Resources
any good free online resources for further reading.
Topic Development
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