- Apnea: especially in infants <2 months or preterm – requires cardiac monitoring
- Respiratory failure: severe retractions, grunting, SpO₂ <90% on 40% O₂
- Dehydration: inadequate oral intake due to respiratory distress
Acute Bronchiolitis (RSV)
Must-Not-Miss / Red Flags
Patient Explanation
“Your baby has a common viral chest infection that makes it harder to breathe. We’ll help with suctioning and oxygen, and most babies recover fully with supportive care.”
Board Fact
“The peak age for bronchiolitis is 2‑6 months; RSV causes 50‑80% of cases during winter months.”
ICD-10
J21.0
Definition & Core Concept
Acute bronchiolitis is a viral lower respiratory tract infection affecting infants, characterized by inflammation of the bronchioles, most commonly caused by respiratory syncytial virus (RSV), leading to cough, wheezing, and respiratory distress.
Epidemiology & Risk Factors
- Most common lower respiratory tract infection in infants <1 year
- Seasonal (November‑March in northern hemisphere)
- Hospitalization rate: 2‑3% of all infants; higher in preterm, congenital heart disease, chronic lung disease
Clinical Vignette
A 3‑month‑old former full‑term infant presents in December with 3 days of nasal congestion and cough, now with rapid breathing and difficulty feeding. Exam: RR 60, SpO₂ 88% on room air, intercostal retractions, and diffuse wheezing. RSV antigen is positive.
Pearls & Pitfalls
- Bronchiolitis is a clinical diagnosis – routine chest X‑ray and viral testing are unnecessary in typical cases.
- Epinephrine and hypertonic saline are not recommended for routine use; supportive care remains the cornerstone.
Discharge & Follow-Up
Follow up with pediatrician in 48‑72 hours after discharge. Educate parents on warning signs: increasing respiratory rate, poor feeding, lethargy. Avoid smoke exposure.
Literature & Guidelines
AAP 2024 Clinical Practice Guideline for Bronchiolitis. PMID: 38741201.