Pediatric Emergencies — Part 2: Pediatric Respiratory Emergencies

1. Croup (Laryngotracheobronchitis)

Croup is the most common cause of acute upper airway obstruction in children aged 6 months to 6 years, with a peak incidence at 1 to 2 years of age. It is caused by viral infection (most commonly parainfluenza types 1 and 3, but also RSV, influenza, adenovirus, and human metapneumovirus) producing inflammation and edema of the subglottic airway. The hallmark triad of barky (seal-like) cough, inspiratory stridor, and hoarseness is usually preceded by 1-3 days of upper respiratory symptoms. Symptoms characteristically worsen at night.^{1 2}

1.1 Westley Croup Severity Score

The Westley Croup Score is the most widely validated and utilized clinical scoring system for assessing croup severity. Scores range from 0 to 17, with higher scores indicating more severe disease.¹

Severity Classification:

1.2 Croup Management Ladder

1.3 Key Points

• Dexamethasone 0.6 mg/kg is the single most effective treatment for croup at all severity levels; benefit seen within 2-4 hours and lasts 24-72 hours
• Lower doses (0.15 mg/kg) have shown comparable efficacy in some studies for mild-moderate croup, but 0.6 mg/kg remains the standard recommended dose
• Nebulized epinephrine provides rapid temporary relief (onset 10-30 minutes) but does not shorten disease course; observe for rebound
• Antibiotics are not indicated — croup is virtually always viral
• Radiographs are not routinely needed — the classic “steeple sign” on AP neck film has poor sensitivity and specificity; obtain imaging only if the diagnosis is uncertain or foreign body is suspected
• Consider bacterial tracheitis if a child with croup-like symptoms has high fever, toxic appearance, and fails to respond to standard therapy^{1 2}

2. Bronchiolitis

Bronchiolitis is the most common lower respiratory tract infection in infants, typically affecting children younger than 2 years (peak 2-6 months). Respiratory syncytial virus (RSV) is responsible for 50-80% of cases, with other causes including rhinovirus, human metapneumovirus, parainfluenza, influenza, and adenovirus. The clinical guideline emphasizes supportive care, as numerous trials have demonstrated no benefit from bronchodilators, corticosteroids, or antibiotics in typical bronchiolitis.^{3 4}

2.1 Clinical Diagnosis and Assessment

Bronchiolitis is a clinical diagnosis. Key features include:

• Age typically <2 years (most commonly <12 months)
• Preceded by 2-4 days of URI symptoms (rhinorrhea, cough, low-grade fever)
• Progressive cough, tachypnea, wheezing, crackles, increased work of breathing
• Difficulty feeding due to respiratory distress

Severity Assessment:

2.2 Management: What Is Recommended

2.3 Management: What Is NOT Recommended

The following interventions have been studied in multiple randomized controlled trials and are specifically not recommended for routine use in bronchiolitis.^{3 4}

2.4 Admission Criteria

2.5 Discharge Criteria

• Maintaining SpO2 ≥90% on room air for ≥4 hours (including during sleep if inpatient)
• Adequate oral intake (≥75% of usual volume)
• Respiratory rate and work of breathing at or near baseline
• Caregiver comfortable with suctioning and monitoring
• Follow-up arranged within 24-48 hours^{3 4}

3. Acute Asthma Exacerbation

Asthma is the most common chronic disease of childhood, affecting approximately 6-8% of children worldwide. Acute exacerbations are among the most frequent pediatric emergency department presentations. Rapid severity assessment and a stepwise escalation approach to bronchodilator, corticosteroid, and adjunctive therapy can prevent respiratory failure and reduce the need for mechanical ventilation.^{5 6}

3.1 Acute Severity Classification

3.2 Stepwise Management of Acute Asthma

Step 1: All Severities — Initial Assessment and Treatment

Step 2: Moderate-Severe — Add Ipratropium and Systemic Steroids

Step 3: Severe — IV Access and Escalation

Step 4: Refractory/Life-Threatening — ICU-Level Interventions

3.3 Disposition

4. Anaphylaxis

Anaphylaxis is a severe, potentially fatal systemic allergic reaction that occurs rapidly (usually within minutes to hours) after exposure to an allergen. In children, the most common triggers are foods (peanut, tree nuts, cow’s milk, egg, shellfish), insect stings, and medications. Rapid recognition and immediate intramuscular epinephrine administration are the cornerstones of treatment. Delays in epinephrine are associated with increased morbidity and mortality.^{7 8}

4.1 Diagnostic Criteria

Anaphylaxis is highly likely when any ONE of the following criteria is met:

1. Acute onset (minutes to hours) of skin/mucosal involvement (urticaria, flushing, angioedema) PLUS at least one of:

   • Respiratory compromise (dyspnea, wheeze, stridor, hypoxia)
   • Hypotension or end-organ dysfunction (collapse, syncope, incontinence)

2. Two or more of the following occurring rapidly after exposure to a likely allergen:

   • Skin/mucosal involvement
   • Respiratory compromise
   • Hypotension or associated symptoms
   • Persistent GI symptoms (crampy abdominal pain, vomiting)

3. Hypotension after exposure to a known allergen for that patient (age-specific: SBP <70 mmHg for 1 month-1 year, <70 + [2 × age] for 1-10 years, <90 mmHg for >10 years)

4.2 Treatment

4.3 Observation Period

• Observe for 4-6 hours minimum after resolution of symptoms to monitor for biphasic reactions (recurrence of symptoms without re-exposure, occurring in 1-20% of cases, typically within 1-72 hours)
• Extended observation (12-24 hours) is recommended for:
  • Severe initial reaction (requiring multiple doses of epinephrine, hypotension, respiratory failure)
  • History of prior biphasic reaction
  • Previous severe anaphylaxis
  • Delayed presentation (>4 hours from exposure to treatment)
  • Poor access to emergency care

4.4 Discharge Requirements

• Prescribe epinephrine auto-injector (0.15 mg for 7.5-25 kg; 0.3 mg for >25 kg) and demonstrate proper technique
• Provide written anaphylaxis action plan
• Instruct on allergen avoidance
• Recommend medical alert identification
• Refer to allergist/immunologist for formal allergy testing
• Consider short course of oral corticosteroid (3-5 days) and antihistamine to reduce risk of biphasic reaction^{7 8}

5. Foreign Body Aspiration

Foreign body aspiration (FBA) is a life-threatening emergency most common in children aged 1-3 years due to the oral phase of development, small airway caliber, and immature swallowing coordination. The most commonly aspirated objects include peanuts, other nuts and seeds, small food items (grapes, hot dogs, carrots), and small toy parts. Organic material causes more severe airway inflammation than inorganic objects.^{9 10}

5.1 Clinical Presentation

5.2 BLS Management of Choking

Conscious Infant (<1 year) with Severe Airway Obstruction:

1. 5 back blows: hold infant face-down along forearm, head lower than trunk, deliver 5 firm back blows between the scapulae with heel of hand
2. 5 chest thrusts: turn infant face-up, deliver 5 chest thrusts (same location as CPR compressions) using 2 fingers
3. Repeat back blows and chest thrusts until object is expelled or infant becomes unresponsive
4. If unresponsive: begin CPR; each time the airway is opened for ventilation, look for the foreign body in the mouth — remove only if visualized; do NOT perform blind finger sweeps in infants/children

Conscious Child (>1 year) with Severe Airway Obstruction:

1. Abdominal thrusts (Heimlich maneuver): stand behind child, place fist above umbilicus and below xiphoid, deliver quick inward-upward thrusts
2. Repeat until object expelled or child becomes unresponsive
3. If unresponsive: begin CPR as above

Mild Obstruction (Effective Cough):

• Encourage coughing; do NOT interfere
• Do NOT perform back blows or abdominal thrusts if the child is coughing effectively, speaking, or breathing
• Monitor closely for deterioration to complete obstruction

5.3 Imaging

5.4 Definitive Management

5.5 Key Points

• Right mainstem bronchus is the most common site of lodging in older children and adults due to its more vertical orientation; in young children, either side may be affected with approximately equal frequency
• Button battery ingestion is a true emergency if lodged in the esophagus — can cause full-thickness esophageal necrosis within 2 hours; honey (10 mL every 10 minutes) may be given en route if battery ingestion was <12 hours ago and child is >12 months old, as it has been shown to reduce tissue injury
• Rigid bronchoscopy is preferred over flexible bronchoscopy for foreign body removal in children because it provides a secure airway, better visualization, and allows passage of larger instruments
• A normal chest radiograph does not exclude foreign body aspiration — sensitivity is only 60-75%; maintain high clinical suspicion based on history^{9 10}

6. Pediatric Upper Airway Emergencies: Differential Diagnosis