Bronchiolitis is a viral infection of the small airways in children under 2, most often caused by RSV, that peaks in winter. It starts like a cold and then causes cough, fast breathing and wheeze, and treatment is supportive with suction, oxygen and fluids.
Key symptoms
- Runny nose and mild fever for a few days
- Cough and fast or noisy breathing
- Poor feeding and fewer wet diapers
- Pauses in breathing in young or premature babies
What you find on exam
- Breathing rate, retractions, nasal flaring and grunting
- Crackles and wheeze on both sides of the chest
- Oxygen saturation and color
- Hydration: mucous membranes, fontanelle, capillary refill
- Pediatric assessment triangle: appearance, work of breathing, circulation
Tests
- Diagnosis is clinical; routine X-rays and blood tests are not needed
- Pulse oximetry
- Viral swab if it changes care, such as in a hospital setting
- Blood gas or glucose only if severe or lethargic
Treatment basics
- Gentle nasal suction, especially before feeds
- Oxygen if saturation stays under 90 percent
- Small frequent feeds; IV or tube fluids if the infant cannot feed
- High-flow nasal cannula or CPAP for increasing work of breathing
- Albuterol, steroids and antibiotics are not routinely helpful
Red flags
- Apnea or blue color
- Severe retractions, grunting or exhaustion
- Not feeding, lethargy or signs of dehydration
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Related guides
Sources: NASEMSO National Model EMS Clinical Guidelines; NCSBN 2026 NCLEX-RN Test Plan. Written by Making Synapses. Making Synapses is not affiliated with these organizations.