Bronchiolitis

Definition and transmission

Bronchiolitis is an epidemic and seasonal viral lower-respiratory infection in children under 2 years, characterised by obstruction of the bronchioles.

Respiratory syncytial virus is responsible for many cases. Transmission occurs directly through inhaled droplets and indirectly through hands or materials contaminated by respiratory secretions.

Most cases are benign, resolve spontaneously, and can be managed as outpatients. Severe cases need hospital care because exhaustion, hypoxia, feeding failure, dehydration, or secondary bacterial infection can occur.

Clinical features

• Rhinopharyngitis with dry cough often precedes lower-airway signs by 24 to 72 hours.
• Typical findings include tachypnoea, dyspnoea, wheeze, cough, and profuse frothy obstructive secretions.
• Auscultation may show prolonged expiration with diffuse bilateral wheezes and sometimes diffuse fine end-inspiratory crackles.
• Fever is often absent or moderate. Cough can persist for 2 weeks or longer even after obstructive symptoms improve.

Severity assessment and admission

• Hospitalise any child with significant deterioration in general condition, toxic appearance, pallor or grey colour, apnoea, cyanosis, marked respiratory distress, anxiety or agitation from hypoxia, altered consciousness, respiratory rate above 60/minute, persistent SpO2 below 92%, sweating, tachycardia at rest without fever, silent chest, or inability to drink or suck.
• Be cautious when distress appears to decrease with a falling respiratory rate; this can indicate exhaustion rather than improvement, especially below 30/minute in infants under 1 year or below 20/minute in children under 3 years.
• Hospitalise children with pre-existing cardiac or pulmonary disease, malnutrition, HIV infection, or another serious comorbidity.
• Consider admission case by case for age under 3 months or associated acute illness such as viral gastroenteritis or bacterial infection.
• Outpatient care is appropriate only when no severity criteria are present and caregivers can perform care and return promptly if warning signs appear.

Outpatient treatment

• Use nasal irrigation with 0.9% sodium chloride before each feed. Demonstrate technique to the caregiver: lay the child on the back, turn the head to one side, and instil saline one nostril at a time.
• Give small frequent feeds to reduce vomiting triggered by coughing bouts. Increase fluids if fever or heavy secretions are present.
• Treat fever using the fever pathway. Handle the child as little as possible and avoid unnecessary procedures.
• Teach caregivers to return urgently for worsening breathing, chest indrawing, apnoea, cyanosis, poor feeding, dehydration, drowsiness, persistent fever, or exhaustion.

Hospital treatment

• Place the infant semi-reclined at about 30 degrees. Continue nasal irrigation, small frequent feeds, and fever treatment as in outpatient care.
• Use gentle oropharyngeal suction only when needed. Avoid unnecessary handling.
• Monitor fluid intake. Usual requirements are about 80 to 100 ml/kg/day plus 20 to 25 ml/kg/day when high fever or very profuse secretions are present.
• Give humidified nasal oxygen for respiratory distress or SpO2 below 92%.
• If vomiting or fatigue prevents sucking, use nasogastric small frequent feeds or IV fluids for the shortest possible time. Avoid oral feeds during severe tachypnoea, but do not prolong NG feeds or IV fluids longer than necessary.

Bronchodilators and antibiotics

• Routine bronchodilator therapy is not indicated.
• A trial may be used in severe respiratory distress: salbutamol MDI 100 micrograms/puff, 2 to 3 puffs with spacer, repeated twice at 30-minute intervals.
• Continue salbutamol only if there is clear clinical improvement, commonly 2 to 3 puffs every 6 hours during the acute phase followed by gradual reduction. Stop if the trial is ineffective.
• Antibiotics are not indicated unless complications such as secondary bacterial pneumonia are suspected.

Prevention, infection control, and handover

• Bronchiolitis spreads readily in hospitals. Cohort affected children away from other children when possible.
• Handwashing after contact with patients, contaminated objects, or nearby surfaces is the most important prevention measure. Staff should use gowns, gloves, and surgical masks during contact according to IPC policy.
• Prevention also includes reducing smoke exposure, breastfeeding support, limiting exposure of young infants to respiratory infections, and keeping routine vaccines up to date.
• Handover should include age, weight, duration, respiratory rate, SpO2, feeding ability, apnoea/cyanosis, work of breathing, auscultation, fluids/feeds, oxygen, suction, bronchodilator trial response, comorbidities, and caregiver return capacity.