Synopsis
Diagnose bronchiolitis clinically, grade respiratory and feeding risk by age and comorbidity, use the correct oxygen and admission thresholds, provide proportionate secretion and hydration support, and avoid ineffective medicines and investigations.
- Bronchiolitis is a clinical diagnosis in a child under 2 years: 1–3 days of coryza followed by persistent cough, tachypnoea or recession and wheeze or crackles, usually peaking on days 3–5.
- Young infants can present with apnoea before typical chest signs. Record gestation, chronological age, comorbidity, feeding and previous apnoea explicitly.
- First-line assessment is respiratory rate, work of breathing, alertness, colour, pulse oximetry with a correctly sized probe, hydration and observed ability to feed.
- Do not diagnose severity from saturation alone. Borderline pulse oximetry can be inaccurate, including overestimation in darker skin; confirm a stable trace and interpret with the child.
- NICE admission thresholds are persistent saturation below 90% from 6 weeks of age, or below 92% under 6 weeks or with an underlying condition; apnoea, severe distress and inadequate intake are independent indications.
- Give supplemental oxygen at the same persistent thresholds. Titrate to remain at or above the relevant threshold and wean only when clinically stable, including through sleep.
- First-line feeding support is small frequent oral feeds if safe. Use nasogastric or orogastric fluids when oral intake is inadequate; use intravenous isotonic fluid if enteral fluid is not tolerated or respiratory failure is impending.
- Consider upper-airway suction only when secretions cause respiratory difficulty or feeding impairment; perform it in an infant with apnoea even if secretions are not obvious.
- Do not routinely use salbutamol, nebulised adrenaline, ipratropium, corticosteroids, antibiotics, hypertonic saline or montelukast. Bronchiolitis is not an asthma exacerbation.
- Do not routinely request chest radiography, blood tests or blood gas analysis. Radiographic changes can imitate pneumonia and drive unnecessary antibiotics.
- Escalate to blood gas and respiratory support for severe worsening distress or suspected failure. High-flow or CPAP decisions follow the local paediatric respiratory pathway and senior review.
- Before discharge, the child must be clinically stable, take adequate oral fluids and maintain room-air saturation for 4 hours including sleep: above 90% from 6 weeks, or above 92% when younger or with underlying disease.
Key red flags
Observed or reported apnoea, central cyanosis, poor respiratory effort, exhaustion or reduced responsiveness requires emergency hospital care.
Severe respiratory distress with grunting, marked recession or respiratory rate above 70 breaths/minute meets a NICE admission criterion.
Persistent room-air oxygen saturation below 90% in a child aged at least 6 weeks, or below 92% under 6 weeks or with an underlying condition, meets an admission and oxygen threshold.
Fluid intake around 50–75% of usual, dehydration or inability to coordinate sucking with breathing may require admission and enteral or intravenous support.
Prematurity, age under 3 months, chronic lung disease, significant congenital heart disease, neuromuscular disease or immunodeficiency lowers the threshold for referral.
High fever, focal crackles, toxic appearance, recurrent focal wheeze or an atypical course should prompt reassessment for pneumonia, sepsis, foreign body or another diagnosis.
Investigation priorities
Confirm the syndrome and determine respiratory, oxygen and feeding support needs.
Management branches
A child under 2 years has a typical bronchiolitis syndrome.
- Measure respiratory effort, saturation where available, hydration and observed or reported intake.
- Arrange emergency transfer for apnoea, cyanosis, severe distress or exhaustion; consider referral for persistent saturation below 92%, rate above 60, dehydration or reduced intake.
- Account for young age, prematurity, comorbidity and caregiver ability, and provide explicit safety-net advice if managed at home.