What is the recommended nebulised management for a child presenting with an acute asthma exacerbation?

Management of Acute Asthma Exacerbation with Nebulisation in Pediatrics

Immediately administer nebulized salbutamol 5 mg (or 2.5 mg for children ≤2 years or <15 kg) via oxygen-driven nebulizer every 20 minutes for three doses in the first hour, combined with high-flow oxygen to maintain SpO₂ >92%, oral prednisolone 1–2 mg/kg (max 40–60 mg), and add ipratropium bromide 100–250 µg to each nebulizer treatment for moderate-to-severe exacerbations. 1

Initial Severity Assessment

Recognize severe exacerbation by these specific features 1:

• Respiratory rate >50 breaths/min (or >35 breaths/min in older children) 1, 2
• Heart rate >140 beats/min 1
• Too breathless to talk or feed 1
• Use of accessory muscles 1
• Peak expiratory flow <50% predicted (in children ≥5 years) 1

Life-threatening features requiring immediate escalation include 1:

• PEF <33% predicted 1
• Silent chest or poor respiratory effort 1
• SpO₂ <92% despite supplemental oxygen 1
• Cyanosis, altered consciousness, or exhaustion 1
• Normal or elevated PaCO₂ (signals impending respiratory failure) 1

First-Hour Intensive Treatment Protocol

Bronchodilator Therapy

Nebulized salbutamol is the cornerstone 1:

• 5 mg via oxygen-driven nebulizer every 20 minutes for three consecutive doses 1, 3
• Reduce to 2.5 mg for children ≤2 years or <15 kg 1, 2
• Alternative agent: terbutaline 10 mg (5 mg for young children) 1

MDI with spacer is equally effective and may reduce admission rates 1, 2:

• 4–8 puffs every 20 minutes for three doses 1
• This delivery method produces fewer cardiovascular side effects 1, 2
• Most children under 7 years cannot use unmodified MDI without spacer 2

Oxygen Therapy

Provide high-flow oxygen via face mask immediately to maintain SpO₂ >92% 1, 2, 3

Systemic Corticosteroids

Administer prednisolone 1–2 mg/kg orally (maximum 40–60 mg) immediately 1, 2:

• Do not delay corticosteroids while giving repeated bronchodilators alone—this is a leading cause of preventable mortality 2
• Continue for 3–5 days without taper if course <10 days 1
• If vomiting or critically ill: IV hydrocortisone 100 mg every 6 hours (or 200 mg every 6 hours per some protocols) 1, 2

Anticholinergic Addition

Add ipratropium bromide 100–250 µg to each nebulizer treatment for moderate-to-severe attacks 1, 4:

• Repeat every 6 hours until improvement begins 1
• The combination of SABA plus ipratropium reduces hospital admission risk (RR 0.73; 95% CI 0.63–0.85; NNTB = 16) 4
• Can be mixed with salbutamol in the nebulizer if used within one hour 5

Reassessment at 15–30 Minutes

Measure PEF (if age ≥5 years), respiratory rate, heart rate, and SpO₂ 1, 2

Response-Guided Management

Good response (PEF >75% predicted, minimal symptoms) 1:

• Continue usual maintenance therapy 1
• Monitor with PEF chart 1
• Arrange follow-up within 48 hours 1

Incomplete response (PEF 50–75% predicted, persistent symptoms) 1:

• Maintain high-flow oxygen 1
• Continue prednisolone 1
• Give nebulized β-agonist every 4 hours 1, 2
• Consider hospital admission 1

Poor response (PEF <50% predicted or ongoing severe features) 1:

• Increase nebulized β-agonist to every 15–30 minutes 1
• Continue ipratropium every 6 hours 1
• Arrange immediate hospital admission 1, 2

Escalation for Refractory Cases

If no improvement after first reassessment 1:

• Increase salbutamol frequency to every 15–30 minutes or switch to continuous nebulization 1
• Continuous nebulization (10 mg/hour) is more efficient than intermittent dosing in severe exacerbations, with higher success rates (adjusted SHR 2.70; 95% CI 1.73–4.22) 6
• Ensure ipratropium is added 1
• Continue oxygen and systemic steroids 1

For life-threatening deterioration 1:

• IV aminophylline 5 mg/kg over 20 minutes followed by 1 mg/kg/hour maintenance 1
• Do NOT give loading dose if child is already on oral theophylline 1, 2
• Prepare for ICU transfer 1

Critical Monitoring Parameters

• Record PEF before and after each β-agonist dose at least four times daily 1, 2
• Continuously monitor SpO₂, aiming for >92% 1, 2
• Watch for tachycardia (expected) and bradycardia (ominous sign) 1

Hospital Admission Criteria

Admit immediately for 1, 2:

• Any life-threatening feature 1
• Persistent severe attack after initial therapy 1
• PEF <50% after 1–2 hours of intensive treatment 1
• Inability of caregivers to manage at home 1
• Early deterioration after bronchodilators 1
• Evening presentations, recent nocturnal symptoms, or prior severe attacks (lower threshold) 1

Prognostic factors predicting treatment failure include 7:

• Previous history of intubation (adjusted OR 6.46) 7
• Receiving <3 doses of nebulized salbutamol in ER (adjusted OR 3.21) 7
• SpO₂ <92% at ER presentation (adjusted OR 3.02) 7
• Exacerbation triggered by pneumonia (adjusted OR 2.67) 7

ICU Transfer Criteria

Transfer to intensive care for 1, 2:

• Worsening PEF despite treatment 1
• Increasing exhaustion or feeble respirations 1
• Persistent/worsening hypoxia (SpO₂ <92%) or hypercapnia 1
• Altered consciousness 1
• Respiratory arrest or coma 1

Critical Pitfalls to Avoid

• Sedatives are absolutely contraindicated in acute pediatric asthma 1, 2
• Do not delay systemic corticosteroids while giving repeated albuterol alone—underuse of corticosteroids is a leading cause of preventable asthma mortality 2
• Do not give aminophylline bolus to children already receiving oral theophylline 1, 2
• Do not rely solely on subjective assessment—obtain objective measurements (PEF, SpO₂) 1
• Avoid leakage around face mask during nebulization, as ipratropium contact with eyes can cause pupil enlargement, blurred vision, or precipitate narrow-angle glaucoma 5

Discharge Criteria (When Stable)

Discharge when 1, 2:

• Stable on discharge medication for ≥24 hours 1
• PEF >75% predicted 1
• Diurnal PEF variability <25% 1
• Minimal or absent symptoms 1
• Verified inhaler technique 1

Prescribe 1:

• Prednisolone 1–2 mg/kg daily to complete 3–5 day course 1
• Continue inhaled corticosteroids alongside bronchodilators 1
• Provide personal PEF meter with written self-management plan 1
• Arrange GP follow-up within 1 week and respiratory clinic review within 4 weeks 1, 2

Levosalbutamol Considerations

Standard guidelines recommend racemic salbutamol 1:

• If levosalbutamol is chosen, use 0.075 mg/kg per dose (minimum 1.25 mg) every 20 minutes for three doses in the first hour 1
• Maintenance: 0.075–0.15 mg/kg every 1–4 hours (practical maximum 1.25 mg) 1
• This represents approximately half the milligram dose of racemic salbutamol 1
• Limited evidence suggests modestly better SpO₂ and PEFR with less tachycardia, but not incorporated into major guidelines 1