What is the most appropriate first-line therapy for a child with moderate to severe acute asthma exacerbation?

First-Line Therapy for Moderate to Severe Acute Asthma Exacerbation in Children

For a child with moderate to severe acute asthma exacerbation, immediately administer high-flow oxygen (to maintain SaO₂ >92%), nebulized salbutamol 5 mg (or 4-8 puffs via MDI with spacer), oral prednisolone 1-2 mg/kg (maximum 60 mg), and add ipratropium 100 mcg to the nebulizer. 1, 2

Immediate Treatment Protocol

Oxygen Therapy

• Administer high-flow oxygen via face mask immediately to maintain oxygen saturation >92% in all children with moderate to severe exacerbation 1, 2
• Continuous pulse oximetry should be maintained throughout treatment 1

Bronchodilator Therapy

• Salbutamol is the cornerstone bronchodilator: Give 5 mg via oxygen-driven nebulizer OR 4-8 puffs via metered-dose inhaler with large volume spacer every 20 minutes for up to 3 doses in the first hour 1, 2
• For children ≤2 years, reduce the nebulized dose to 2.5 mg 2
• MDI with spacer is equally effective to nebulization and may result in lower admission rates, particularly in severe exacerbations, with fewer cardiovascular side effects 1

Anticholinergic Addition

• Add ipratropium 100 mcg to the nebulizer immediately for moderate to severe exacerbations 1, 2
• Repeat ipratropium every 6 hours until improvement starts 3, 1
• The combination of beta-agonist plus ipratropium significantly reduces hospitalizations, particularly in patients with severe airflow obstruction 1, 4

Systemic Corticosteroids

• Administer oral prednisolone 1-2 mg/kg (maximum 60 mg) immediately, ideally within the first hour 1, 2, 5
• Oral corticosteroids are preferred when the child can swallow and is not vomiting, as there is no advantage to intravenous administration when gastrointestinal transit is normal 1
• Reserve intravenous hydrocortisone (200 mg every 6 hours or 4 mg/kg/dose every 6 hours) only for children who are vomiting, seriously ill, or unable to take oral medications 3, 1
• Underuse of corticosteroids is specifically identified as a leading cause of preventable asthma mortality—do not delay administration 1

Assessment of Severity

Features Indicating Severe Exacerbation

• Too breathless to talk or feed 3, 1
• Respiratory rate >50 breaths/minute 3, 1
• Pulse >140 beats/minute 3, 1
• Peak expiratory flow <50% predicted 3, 1
• Use of accessory muscles 1

Life-Threatening Features Requiring Escalation

• Peak flow <33% predicted or poor respiratory effort 3, 1
• Silent chest, cyanosis, or exhaustion 3, 1
• Altered level of consciousness or agitation 3, 1
• Oxygen saturation <92% despite supplemental oxygen 1

Monitoring and Reassessment

• Repeat peak expiratory flow measurement 15-30 minutes after starting treatment 3, 1
• Reassess clinical status after each set of bronchodilator doses 1, 2
• Chart PEF before and after β-agonist administration at least 4 times daily throughout hospital stay 3, 1
• Response to treatment in the emergency department is a better predictor of hospitalization need than initial severity 1

Subsequent Management Based on Response

If Patient is Improving After Initial Treatment

• Continue high-flow oxygen 3, 1
• Continue prednisolone 1-2 mg/kg daily (maximum 40 mg) 3, 1
• Continue nebulized β-agonist 4 hourly 3, 1

If Patient is NOT Improving After 15-30 Minutes

• Continue oxygen and steroids 3, 1
• Increase nebulized β-agonist frequency up to every 30 minutes 3, 1
• Ensure ipratropium is added if not already given 3, 1
• Consider intravenous magnesium sulfate for life-threatening exacerbations or those remaining severe after 1 hour of intensive conventional treatment 1, 4

Critical Pitfalls to Avoid

• Do not delay systemic corticosteroids while giving repeated albuterol doses alone—this is a common cause of treatment failure and preventable mortality 1
• Do not use sedatives of any kind in acute severe asthma, as they can depress respiratory function 1
• Do not use antibiotics unless bacterial infection is confirmed—viral respiratory infections are the most common trigger for asthma exacerbations in children 1
• Do not use intravenous aminophylline as first-line therapy; reserve it for patients not improving after initial treatment 1
• Ensure proper inhaler technique and age-appropriate device before escalating therapy—inadequate technique is a common cause of treatment failure 1, 6

Hospital Admission Criteria

• Persistent features of severe asthma after initial treatment 1
• Peak expiratory flow remaining <50% predicted 15-30 minutes after nebulization 3, 1
• Life-threatening features present 1
• Parents unable to give appropriate treatment at home 1

Transfer to Intensive Care Unit

Transfer accompanied by a physician prepared to intubate if there is: 3, 1

• Deteriorating peak flow or worsening exhaustion
• Persistent hypoxemia or hypercapnia (PaCO₂ ≥42 mm Hg)
• Altered consciousness, confusion, or drowsiness
• Respiratory arrest