A 14-week-old male infant was brought to the emergency department with fever, cough, and progressive respiratory distress. Caregivers reported three days of rhinorrhea and nasal congestion followed by worsening cough and decreased feeding over the preceding 24 hours. During the last 10 hours, the infant developed post-tussive emesis, tactile fever, and increased work of breathing.
The infant was born at term without perinatal complications and received routine immunisations at two months of age. There was no prior history of wheezing or cardiopulmonary disease. A school-aged sibling at home had recent upper respiratory symptoms.
On presentation, the infant appeared in moderate respiratory distress. Vital signs showed a temperature of 39.1 °C, a heart rate of 162 bpm, a respiratory rate of 68 breaths/min, and an oxygen saturation of 88% on room air. Physical examination revealed marked nasal congestion, subcostal and intercostal retractions, nasal flaring, and intermittent head bobbing. Diffuse expiratory wheezes were audible bilaterally without focal crackles.
Initial management in the emergency department included gentle nasal suctioning, supplemental oxygen via blow-by, and a trial of inhaled bronchodilator without clinical improvement. The infant was admitted to the pediatric floor on a low-flow nasal cannula at 1.5 L/min with oxygen saturation improving to 92%, though moderate work of breathing persisted.
Chest radiography demonstrated mild peribronchial thickening without focal consolidation or cardiomegaly. A respiratory viral panel was obtained.
Given the clinical picture, the patient was diagnosed with acute viral bronchiolitis with hypoxemic respiratory distress. Supportive management, including airway clearance, oxygen therapy, and hydration monitoring, was continued. Viral testing later returned positive for respiratory syncytial virus (RSV). The infant improved over 48 hours and was discharged home with caregiver education and close follow-up.
Introduction
Acute bronchiolitis is the leading cause of lower respiratory tract hospitalisation in infants during the first year of life. The respiratory syncytial virus is the most common cause, although multiple viral pathogens may cause a similar clinical syndrome. The disease is characterised by inflammation, oedema, and mucus plugging of the small airways, resulting in increased work of breathing and ventilation–perfusion mismatch. Early recognition and appropriate supportive care remain the cornerstones of management.
Discussion
This case illustrates the typical progression of viral bronchiolitis in early infancy. The combination of upper respiratory prodrome, feeding difficulty, wheezing, and increased work of breathing strongly supported the diagnosis. Importantly, infants are obligate nasal breathers; therefore, nasal obstruction from tenacious secretions significantly contributes to respiratory distress.
Current evidence emphasises supportive care rather than routine pharmacologic therapy. Gentle nasal suctioning is the most effective first-line intervention for improving airflow. Supplemental oxygen is recommended when oxygen saturation persistently falls below accepted thresholds. Bronchodilators are generally not beneficial in previously healthy infants and may expose patients to unnecessary adverse effects.
Radiographic and laboratory investigations are not routinely required but may be considered in young infants or when alternative diagnoses are suspected. Hydration status requires close monitoring, as tachypnea and poor feeding commonly lead to fluid deficit and thicker airway secretions.
Most infants demonstrate clinical improvement within several days with supportive therapy alone. Escalation to high-flow nasal cannula or non-invasive ventilation may be required in cases of worsening respiratory distress or persistent hypoxemia.
Conclusion & Learning Points
· Viral bronchiolitis should be suspected in young infants with URI prodrome followed by wheezing and increased work of breathing.
· Infants are obligate nasal breathers; effective nasal suctioning is a key therapeutic intervention.
· Routine bronchodilator use is not recommended in typical bronchiolitis without a prior wheezing history.
· Oxygen therapy should be titrated to maintain target saturations while avoiding unnecessary supplementation.
· Careful hydration assessment is essential due to feeding intolerance and increased insensible losses.
