What is the recommended levosalbutamol nebulisation regimen for a child presenting with an acute asthma exacerbation?

Levosalbutamol Nebulisation for Acute Pediatric Asthma Exacerbation

For a child with acute asthma exacerbation, administer levosalbutamol 0.075 mg/kg per dose (minimum 1.25 mg) via oxygen-driven nebulizer every 20 minutes for three consecutive doses in the first hour, then continue at 0.075–0.15 mg/kg every 1–4 hours based on clinical response. 1

Initial Intensive Phase (First Hour)

• Give levosalbutamol 0.075 mg/kg per dose (minimum 1.25 mg, practical maximum 1.25 mg for most children) via oxygen-driven nebulizer every 20 minutes for three doses during the first hour of presentation 1

• This weight-based regimen provides approximately half the milligram dose of racemic salbutamol while achieving comparable bronchodilation 1

• For children ≤2 years or <15 kg, use the minimum dose of 1.25 mg per nebulization 1

• Deliver via oxygen-driven nebulizer to maintain SpO₂ >92% throughout treatment 2, 1

Concurrent Essential Therapy

• Administer oral prednisolone 1–2 mg/kg (maximum 40–60 mg) immediately upon recognition of the exacerbation; if the child is vomiting or critically ill, give IV hydrocortisone 100 mg every 6 hours 1, 3

• Add ipratropium bromide 100–250 µg to each nebulizer treatment for moderate-to-severe attacks; repeat every 6 hours until improvement begins 2, 1

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

Reassessment at 15–30 Minutes

• Measure peak expiratory flow (if age ≥5 years), respiratory rate, heart rate, and SpO₂ after the initial intensive phase 1

Response-Guided Continuation

• Good response (PEF >75% predicted, minimal symptoms): continue levosalbutamol 0.075–0.15 mg/kg every 4 hours as needed, maintain controller therapy, arrange follow-up within 48 hours 1

• Incomplete response (PEF 50–75% predicted, persistent symptoms): continue levosalbutamol every 4 hours, maintain oxygen and prednisolone, consider hospital admission 1

• Poor response (PEF <50% predicted or ongoing severe features): increase levosalbutamol frequency to every 15–30 minutes or switch to continuous nebulization at the same per-dose amount, continue ipratropium every 6 hours, arrange immediate admission 1

Evidence Base for Levosalbutamol

• International pediatric asthma guidelines (British Thoracic Society, Global Initiative for Asthma) recommend racemic salbutamol as the standard bronchodilator for acute attacks 2, 1

• Small comparative studies suggest levosalbutamol may yield modestly better SpO₂, PEFR, and asthma scores with less tachycardia and hypokalemia compared to racemic salbutamol 4, 5, though one ED study found no difference 6

• The evidence for levosalbutamol superiority is limited and not incorporated into major guidelines; if chosen, apply the same escalation protocol described for standard salbutamol 1

Safety Monitoring

• When levosalbutamol is given at higher doses or frequent intervals, monitor for tachycardia, tremor, and hypokalemia as expected adverse effects 1

• Levosalbutamol appears to cause less tachycardia and less hypokalemia than racemic salbutamol at equivalent bronchodilator doses 4, 5

Hospital Admission Criteria

• Admit immediately for any life-threatening feature (PEF <33% predicted, silent chest, cyanosis, poor respiratory effort, altered consciousness, SpO₂ <92% despite oxygen) 2, 1

• Admit for persistent severe attack after initial therapy, PEF <50% after 1–2 hours of intensive treatment, inability of caregivers to manage at home, or early deterioration after bronchodilators 1

• Apply a lower threshold for admission for evening presentations, recent nocturnal symptoms, prior severe attacks, or poor social support 2, 1

Critical Pitfalls to Avoid

• Never delay systemic corticosteroids while giving repeated bronchodilator doses alone—this is a common cause of treatment failure and preventable mortality 1, 3

• Do not give an aminophylline bolus to children already receiving oral theophylline 2, 1

• Sedatives are absolutely contraindicated in acute pediatric asthma 1

• Do not rely solely on subjective assessment—obtain objective measurements (PEF if age-appropriate, SpO₂) to guide escalation 2, 1

Escalation for Refractory Cases

• If no improvement after the first reassessment, increase levosalbutamol frequency to every 15–30 minutes or switch to continuous nebulization, ensure ipratropium is added, and continue oxygen and systemic steroids 1

• For life-threatening deterioration, give IV aminophylline 5 mg/kg over 20 minutes followed by maintenance infusion of 1 mg/kg/hour; prepare for ICU transfer 2, 1