Emergency Medicine · Year 3 · from Emergency Medicine

Case 1: Bronchiolitis - The Wheezing Infant

Patient Demographics

• Age: 4 months
• Sex: Female
• Accompanied by: Mother

Chief Complaint

"She's breathing really fast and won't eat."

History of Present Illness

Mother brings her 4-month-old daughter for evaluation of respiratory distress. Illness began 3 days ago with rhinorrhea and mild cough. Over the past 24 hours, infant has developed increased work of breathing, wheezing audible without stethoscope, and poor feeding (taking only 50% of usual bottle volumes). Mom reports fewer wet diapers today. Older sibling (3 years) had a "cold" last week.

Initial Assessment

Pediatric Assessment Triangle (PAT):

• Appearance: Alert but tired-appearing, consolable
• Work of Breathing: Increased - subcostal retractions, nasal flaring
• Circulation: Slightly pale, cap refill 2 seconds

ESI Level: 2 - Respiratory distress in young infant

Vital Signs:

• Heart rate: 168 bpm
• Respiratory rate: 68 breaths/min
• SpO2: 89% on room air
• Temperature: 38.2C (100.8F) rectal
• Weight: 5.8 kg (25th percentile)
• Blood pressure: Not initially obtained

Primary Survey (Pediatric Approach)

Airway:

• Patent, no stridor
• Copious nasal secretions

Breathing:

• Tachypneic (RR 68, normal for age <60)
• Subcostal and intercostal retractions
• Nasal flaring present
• Diffuse expiratory wheezes and crackles bilaterally
• Prolonged expiratory phase

Circulation:

• Tachycardic (appropriate for age and fever)
• Capillary refill 2 seconds
• Slightly mottled extremities

Disability:

• Alert, tracking, appropriate interaction
• Normal fontanelle (soft, flat)
• Normal tone

Exposure:

• No rashes
• No signs of abuse/neglect

Respiratory Distress Assessment

Severity Indicators:

Secondary Survey

SAMPLE History:

• Symptoms: Cough, rhinorrhea, respiratory distress, poor feeding, decreased urine output
• Allergies: None known
• Medications: None
• PMH: Full-term, healthy, no prior hospitalizations
• Last Meal: Attempted bottle 2 hours ago, took 30mL
• Events: Sick contact (sibling)

Birth/Developmental History:

• Born at 39 weeks, uncomplicated delivery
• Birth weight 3.2 kg
• Up to date on immunizations
• Meeting developmental milestones
• No prior wheezing episodes

Risk Factors for Severe Bronchiolitis:

• Age <12 weeks: No (4 months)
• Prematurity: No
• Chronic lung disease: No
• Congenital heart disease: No
• Immunodeficiency: No
• Neuromuscular disease: No

Physical Examination

HEENT:

• Copious clear nasal discharge
• Oropharynx mildly erythematous
• TMs normal bilaterally
• Fontanelle soft, flat

Respiratory:

• Tachypneic with retractions
• Diffuse wheezes and crackles
• Good air entry bilaterally
• No focal findings

Cardiovascular:

• Tachycardic, regular rhythm
• No murmur
• Pulses 2+ throughout

Abdomen:

• Soft, non-tender
• No hepatosplenomegaly

Skin:

• Mildly dry mucous membranes
• Skin turgor slightly decreased

Diagnostic Testing

Point-of-Care:

• Respiratory viral panel (nasal swab): RSV positive
• Glucose: 78 mg/dL

Labs (not routinely indicated, obtained due to severity):

• CBC: WBC 11.2, Hgb 11.8
• BMP: Na 136, K 4.8, HCO3 22, Glucose 82

Chest X-ray: Hyperinflation, perihilar infiltrates, no focal consolidation (classic bronchiolitis pattern)

Diagnosis

Acute bronchiolitis secondary to Respiratory Syncytial Virus (RSV)

Management

Evidence-Based Bronchiolitis Treatment:

What DOES work:

1. Supplemental oxygen: Nasal cannula at 1L/min, goal SpO2 >90%
2. Nasal suctioning: Bulb suction before feeds and PRN
3. Hydration: IV fluids initiated (D5 1/2 NS at maintenance rate)
4. Monitoring: Continuous pulse oximetry, respiratory assessment

What does NOT work (avoid routinely):

• Bronchodilators (albuterol) - no proven benefit in bronchiolitis
• Corticosteroids - no benefit
• Antibiotics - unless bacterial superinfection
• Chest physiotherapy - no benefit

Trial of Bronchodilator:

• One-time albuterol trial considered
• If clear response, may continue; if no response, discontinue
• This patient: No significant response to albuterol trial - discontinued

Clinical Course

First 6 hours:

• SpO2 92-94% on 1L NC
• Respiratory rate decreased to 54
• Tolerated 60mL formula by mouth
• Fewer retractions

Admission Criteria (met by this patient):

• Age <12 months with significant respiratory distress
• Hypoxia requiring supplemental oxygen
• Inadequate oral intake
• Apnea history (not present here)
• High-risk underlying conditions (not present)

Disposition

• Admitted to pediatric floor
• Weaned oxygen over 48 hours
• Improved feeding
• Discharged home day 3
• Return precautions provided
• Follow-up with pediatrician in 2-3 days

Teaching Points

1. RSV is the most common cause: Peak age 2-6 months; almost all children infected by age 2
2. Diagnosis is clinical: Viral testing confirms etiology but doesn't change management
3. Supportive care is mainstay: Oxygen, suction, hydration - no specific treatment
4. Bronchodilators generally don't work: Unlike asthma, bronchiolitis involves inflammation and mucus, not bronchospasm
5. Admission criteria: Hypoxia, poor feeding, young age, high-risk conditions
6. Natural history: Typically worsens days 3-5, then improves; full recovery 2-3 weeks
7. Prevention: Palivizumab (RSV antibody) for high-risk infants; hand hygiene critical

Clinical Image

Image Description: Pediatric chest radiograph demonstrating hyperinflation of the lungs with flattened diaphragms, perihilar infiltrates, and peribronchial thickening consistent with acute viral bronchiolitis.

Attribution: Image from Radiopaedia.org, Case courtesy of Dr. Jeremy Jones. Licensed under CC BY-NC-SA 3.0. Source: https://radiopaedia.org/cases/bronchiolitis-2

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