What is the recommended levosalbutamol nebuliser dose and maximum dose for children with an acute asthma exacerbation?

Levosalbutamol Nebulization Dosing in Pediatric Acute Asthma

For acute asthma exacerbations in children, administer levosalbutamol 0.075 mg/kg (minimum 1.25 mg) via nebulizer every 20 minutes for 3 doses in the first hour, then 0.075–0.15 mg/kg every 1–4 hours as needed, with a practical maximum single dose of 1.25 mg for most children. 1

Standard Dosing by Age & Weight

Children 6–11 Years (Maintenance & Mild Exacerbations)

• Routine dosing: 0.31 mg three times daily via nebulizer 2
• Maximum routine dose: 0.63 mg three times daily 2

Children ≥12 Years & Adolescents (Maintenance & Mild Exacerbations)

• Starting dose: 0.63 mg three times daily, every 6–8 hours 2
• Severe asthma or inadequate response: 1.25 mg three times daily 2
• Patients receiving 1.25 mg doses require close monitoring for systemic adverse effects 2

Acute Exacerbation Protocol (All Pediatric Ages)

First Hour (Intensive Phase)

• Weight-based dosing: 0.075 mg/kg per dose (minimum 1.25 mg) 1
• Frequency: Every 20 minutes for 3 doses 1
• For children <15 kg or ≤2 years: Use half the standard adult dose (approximately 0.625–1.25 mg) 3

After Initial Hour (Maintenance Phase)

• Dosing range: 0.075–0.15 mg/kg every 1–4 hours as needed 1
• Practical maximum: 1.25 mg per dose for most children 1, 2
• Adult equivalent: 1.25–2.5 mg every 1–4 hours 1

Maximum Dose Considerations

There is no absolute maximum daily dose specified in guidelines, but the following principles apply:

• Levosalbutamol is administered at half the milligram dose of racemic albuterol to provide comparable efficacy and safety 1
• For severe refractory exacerbations, frequency may be increased to every 15–30 minutes or switched to continuous nebulization rather than increasing individual dose size 3
• The FDA-approved maximum for routine outpatient use is 1.25 mg three times daily in children ≥12 years 2
• In acute hospital settings, dosing every 1–4 hours can continue as long as medically indicated, with close monitoring for tachycardia, tremor, and hypokalemia 1, 2

Delivery & Administration

• Nebulizer systems: Safety and efficacy established with PARI LC Jet™, PARI LC Plus™ nebulizers and PARI Master® compressors 2
• Do not mix levosalbutamol with other drugs in the nebulizer; compatibility has not been established 2
• Oxygen-driven nebulization is preferred in moderate-to-severe exacerbations to maintain SpO₂ >92% 3

Clinical Algorithm for Dose Escalation

1. Mild exacerbation (PEF >75% predicted, minimal symptoms):

   • 0.31–0.63 mg every 4–6 hours as needed 2

2. Moderate exacerbation (PEF 50–75% predicted, persistent symptoms):

   • 0.075 mg/kg (min 1.25 mg) every 20 minutes × 3 doses 1
   • Reassess at 15–30 minutes 3
   • If improving: continue 0.075–0.15 mg/kg every 4 hours 1

3. Severe exacerbation (PEF <50% predicted, severe symptoms):

   • 0.075 mg/kg (min 1.25 mg) every 20 minutes × 3 doses 1
   • Add ipratropium 100–250 µg to each nebulizer 3
   • If no improvement after 1 hour: increase frequency to every 15–30 minutes 3
   • Consider continuous nebulization for life-threatening features 3

4. Life-threatening features (PEF <33%, silent chest, altered mental status):

   • Continuous nebulization or every 15 minutes 3
   • Immediate hospital admission and ICU consideration 3

Evidence Comparison: Levosalbutamol vs Racemic Salbutamol

While international guidelines recommend racemic salbutamol as the standard bronchodilator 3, recent pediatric studies suggest levosalbutamol may offer modest advantages:

• Better SpO₂ improvement: 97.2% vs 95.0% (p<0.05) 4
• Better PEFR: 159.6 L/min vs 143.8 L/min (p<0.05) 4, 5
• Less tachycardia: HR 115.5 vs 124.5 bpm (p<0.05) 4, 5
• Less hypokalemia: No significant K⁺ drop vs significant decrease with racemic form 5

However, these studies are small and not incorporated into major guidelines 3. If levosalbutamol is chosen, apply the same escalation protocol described above 3.

Critical Pitfalls to Avoid

• Never delay systemic corticosteroids while giving repeated bronchodilator doses alone; prednisolone 1–2 mg/kg (max 40–60 mg) must be given immediately 3
• Never administer sedatives to children with acute asthma—this is absolutely contraindicated 3
• Do not rely on subjective assessment; always measure objective parameters (SpO₂, respiratory rate, PEF if age ≥5 years) 3
• Do not give aminophylline bolus to children already on oral theophylline 3
• Monitor for adverse effects when using high-dose or frequent levosalbutamol: tachycardia (expected), tremor, and hypokalemia 1, 2

Adjunctive Therapy Requirements

Every child receiving levosalbutamol for acute exacerbation must also receive:

• Systemic corticosteroids: Prednisolone 1–2 mg/kg (max 40–60 mg) orally immediately, continued for 3–5 days 3
• Oxygen: High-flow via face mask to maintain SpO₂ >92% 3
• Ipratropium bromide: 100–250 µg added to nebulizer for moderate-to-severe exacerbations, repeated every 6 hours 3

Reassessment & Disposition

• Measure response 15–30 minutes after first dose 3
• Good response (PEF >75%, minimal symptoms): Continue every 4 hours, arrange 48-hour follow-up 3
• Incomplete response (PEF 50–75%): Continue hourly, consider admission 3
• Poor response (PEF <50%): Increase to every 15–30 minutes, immediate hospital admission 3