Acute bronchiolitis is a viral infection of the small airways that mainly affects children under 2 years, most often caused by RSV. It starts like a cold and then leads to cough, wheeze and labored breathing that usually peak on days 3 to 5.
Key symptoms
- Runny nose and mild fever at the start
- Cough, wheezing and fast breathing
- Poor feeding and fewer wet diapers
- Pauses in breathing (apnea) in young infants
What you find on exam
- Respiratory rate, oxygen saturation and level of alertness
- Retractions, nasal flaring, grunting or head bobbing
- Fine crackles and wheezes on both sides
- Hydration status: mucous membranes, capillary refill, fontanelle
Tests
- Diagnosis is clinical; routine tests are not needed
- Pulse oximetry
- Viral testing only when it changes care or isolation
- Chest X-ray only if severe or an atypical course
Treatment basics
- Nasal suctioning, especially before feeds
- Oxygen if saturation stays below about 90 percent
- Fluids by mouth, nasogastric tube or IV if not feeding well
- High-flow nasal cannula for increased work of breathing
- Bronchodilators, steroids and antibiotics are not recommended routinely
Red flags
- Apnea or cyanosis
- Severe retractions, grunting or exhaustion
- Very young infant, prematurity or poor feeding with dehydration
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Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations; NCSBN 2026 NCLEX-RN Test Plan. Written by Making Synapses. Making Synapses is not affiliated with these organizations.