What’s New in Bronchiolitis

Bronchiolitis is a clinical diagnosis in children under 2, and routine chest radiographs, labs, and respiratory viral panels usually add little. Supportive care drives outcomes, while steroids and routine beta-agonists do not; lung ultrasound and emerging bronchiolitis endotypes may refine bedside decisions.

Diagnosis and Natural History

• Clinical diagnosis first: Bronchiolitis is diagnosed from history and exam, not testing, with classic fever, rhinorrhea, cough, crackles, wheeze, or apnea in a child younger than 2 years.
• Testing usually unnecessary: Chest radiographs, routine labs, and respiratory viral panels generally do not improve management and often add noise to a straightforward bronchiolitis presentation.
• Lung ultrasound clues: Adjacent B-lines, hyperechoic areas, and air bronchograms on lung ultrasound track with more severe disease and can help separate bronchiolitis from reactive airway disease. We get into the bedside distinction in the episode.
• Expected illness timeline: Symptoms typically peak on illness days 3 to 5, improve over 1 to 2 weeks, and are resolved in roughly 90% of children by 2 to 3 weeks.
• Escalation warning signs: If impending respiratory failure is a concern, a blood gas can reveal CO2 retention and respiratory acidosis before the child declares themselves clinically.

Management and Disposition

• Supportive care essentials: Nasal suction, hydration, and oxygen remain the core therapies, with suction especially useful before checking saturations and before feeds.
• Oxygen target strategy: Use the lowest oxygen flow that maintains a pulse oximetry above 92%, escalating support only when simple oxygen no longer corrects hypoxemia.
• Noninvasive respiratory support: High-flow nasal oxygen at 1 to 2 L/kg is a common next step, while CPAP around 7 cm H2O is reserved for more severe bronchiolitis.
• Therapies to avoid: Steroids, racemic epinephrine, antibiotics, and chest physiotherapy are not recommended routine treatments for bronchiolitis.
• Beta-agonist controversy: AAP guidance recommends against even a trial of inhaled beta-agonists, though emerging endotype data suggest a subset with atopic or reactive-airway features may differ. We cover that nuance in the chapter.
• Admission risk factors: Hypoxemia, dehydration, increased work of breathing, young age under 2 months, and comorbidities like prematurity, congenital heart disease, or immunodeficiency all push toward admission.

References:

1. Manti S, et al. UPDATE - 2022 Italian guidelines on the management of bronchiolitis in infants. Ital J Pediatr. 2023;49(1):19. Published 2023 Feb 10. PMID: 36765418.
2. Garcia-Garcia ML, et al. Nasal TSLP and periostin in infants with severe bronchiolitis and risk of asthma at 4 years of age. Respir Res. 2023;24(1):26. Published 2023 Jan 24. PMID: 36694181.
3. Gutiérrez Moreno M, et al. High-Flow Oxygen and Other Noninvasive Respiratory Support Therapies in Bronchiolitis: Systematic Review and Network Meta-Analyses. Pediatr Crit Care Med. 2023;24(2):133-142. PMID: 36661419.
4. Guglielmo RD, et al. High-Flow Nasal Cannula Reduces Effort of Breathing But Not Consistently via Positive End-Expiratory Pressure. Chest. 2022;162(4):861-871. PMID: 35305971.
5. Gray S, et al. Oral Feeding on High-Flow Nasal Cannula in Children Hospitalized With Bronchiolitis. Hosp Pediatr. 2023;13(2):159-167. PMID: 36628547.
6. Milési C, et al. Clinical practice guidelines: management of severe bronchiolitis in infants under 12 months old admitted to a pediatric critical care unit. Intensive Care Med. 2023;49(1):5-25. PMID: 36592200.
7. Baudin F, et al. Physiological Effect of Prone Position in Children with Severe Bronchiolitis: A Randomized Cross-Over Study (BRONCHIO-DV). J Pediatr. 2019;205:112-119.e4. PMID: 30448014.
8. Buendía JA, et al. Systematic review and meta-analysis of efficacy and safety of continuous positive airways pressure versus high flow oxygen cannula in acute bronchiolitis. BMC Pediatr. 2022;22(1):696. Published 2022 Dec 3. PMID: 36463122.