Pathophysiology
  • Disorder that is commonly caused by a viral lower respiratory tract infection in infants
  • Characterized by acute inflammation, edema and necrosis of epithelial cells lining small airways and increased mucus production

  • Etiology
    • Coronavirus
    • Influenza
    • Rhino virus
    • Adenovirus
    • Parainfluenza virus
    • RSV (respiratory syncytial virus) – MOST COMMON!
  • Incidence – December-March
      • Most infections occur within first 2 years of life
      • About 40% experience lower respiratory infection during initial infection
      • RSV doesn’t grant permanent or long-term immunity – RE-INFECTION COMMON
      • The risk of significant viral or bacterial lower respiratory tract infection or pneumonia in an infant is low
  • Transmission
    • Direct contact with secretions
    • Young children shed virus for >2 weeks
    • 30-70% of household contacts become ill
  • Natural history
    • Begins with URI – Rhinorrhea, congestion, cough
    • Progresses to LRI in 2-6 days – Airway obstruction (tachypnea, wheezing, respiratory distress)
    • Variable and dynamic course
    • Lasts 2-4 weeks

Case

7-month-old male presents to the emergency room with his parents due to cough, runny nose, congestion and SOB that started 3 days ago.

VS: RR – 65, HR – 140, Temp – 99.1°F, O2 sat – 93% on RA


History
  • Typical Presentation of Bronchiolitis
    • Viral URI and cough with signs of lower respiratory tract infection
      • Work of breathing – grunting, nasal flaring, intercostal/subcostal retractions
      • Tachypnea
      • Wheeze
      • Coarse rales

Physical Exam
  • TIPS for a better exam
    • Upper airway obstruction can contribute to work of breathing
    • Suctioning and positioning may decrease the work of breathing and improve the quality of your examination
    • Counting respiratory rate over the course of 1 min is more accurate than shorter observations
  • Assess mental status, respiratory rate, work of breathing, oxygen status, listen to breath sounds, and assess hydration status


Diagnosis
  • DIAGNOSIS IS CLINICAL – NO LABS OR RADIOLOGICIAL STUDIES ARE NEEDED
    • When to consider CXR – if child has had >2 days of fever, an asymmetric chest exam, does not demonstrate improvement or has an unusually high O2 need
    • Diagnostic testing may be considered if:
      • Need cohorting – this is why we get testing for those we admit
      • Uncertain clinical diagnosis
      • Age <2 months
      • To assess for influenza – also needed this for those we admit

Management

Classify patient as mild, moderate, or severe based on the above physical exam

Mild Moderate Severe
1. Consider suction bulb

2. Discharge

1. Suction bulb

2. No bronchodilators

3. Discharge or admit

1. Suction bulb or wall

2. No bronchodilators

3. If no improvement consider starting high flow NC

4. Admit

  • Rehydration
    • IVF – moderately or severely dehydrated, secretions are thick and difficult to mobilize or severe respiratory distress
    • PO feeds – mildly to moderately dehydrated and can tolerate PO
  • Considerations for severely ill patients
    • Consider ONE TIME albuterol MDI trial if:
      • Severe respiratory distress OR
      • Increased risk for asthma
        • >12 months old, wheeze and once of the following
          • personal history of atopy or recurrent wheezing
          • strong family history of atopy or asthma
        • if responds to albuterol then consider switching to asthma pathway
      • Consider HFNC for significant hypoxia OR severe respiratory distress not improving with rigorous supportive care

 

Discharge criteria Admission criteria
–       Oxygen saturation >90%

–       Awake

–       Adequate oral intake

–       Mild/moderate work of breathing

–       Reliable caretaker

–       Able to obtain follow up care

–       MDI/spacer teaching if response to albuterol

–       Admit if discharge criteria not met:

o   Inpatient: Requires 02 or progression expected

o   OBS: Mild disease with expected LOS < 24 hours

o   ICU: Apnea, severe distress; Requires HFNC / CPAP / intubation

–       Infants with these risk factors present early in the illness have higher risk of progression:

o   Gestational age < 34 weeks

o   Respiratory rate ≥ 70

o   Age < 3 months

Additional Notes
  • Differentiate infants with probable viral bronchiolitis from those with other disorders
  • The above management points to do take into consideration patients with significant medical history such as congenital heart disease, anatomic airway defects, neuromuscular disease, immunodeficiency, chronic lung disease – ADMIT, HIGH RISK!
  • The physical exam will vary from minute to minute depending on child’s position, level of alertness, response to treatment – CONSTANTLY RE-EVALUATE!
  • If patient presents within the first couple of days, they may worsen and need admission at a later point – PARENT EDUCATION IS KEY!
    • Viral illness, treated by hydration and suction
    • Signs of respiratory distress
    • How to suction
    • When to suction
    • Frequent feeds and watch hydration status
    • Cough may last 2-4 weeks, do not use OTC cough and cold medications
    • Avoid tobacco smoke
  • NOT RECOMMENDED!
    • Albuterol – Wheezing is due to the airways being clogged with debris not bronchospasm
    • Racemic epinephrine
    • Corticosteroids
    • Chest physiotherapy
    • Montelukast
    • Antibiotics
    • Hypertonic Saline
    • Routine testing
    • Chest X-rays

References

  1. http://pediatrics.aappublications.org/content/134/5/e1474
  2. http://www.chop.edu/clinical-pathway/bronchiolitis-emergent-evaluation-clinical-pathway
  3. http://www.cochrane.org/CD001266/ARI_bronchodilators-for-bronchiolitis-for-infants-with-first-time-wheezing
  4. http://www.seattlechildrens.org/healthcare-professionals/gateway/pathways/

Special thanks to Dr. Hima Khamar, MD PGY-2 for her contribution to this month’s Pediatric Pearls!