What is the maximum nebulised dose of levosalbutamol (levalbuterol) for a child aged 6‑11 years during an acute asthma exacerbation, including per‑dose limit and dosing frequency?

Maximum Levosalbutamol Dose in Acute Asthma Exacerbation (Ages 6–11 Years)

For children aged 6–11 years with an acute asthma exacerbation, administer nebulized levosalbutamol 0.31–1.25 mg every 20 minutes for three doses during the first hour, then 0.31–1.25 mg every 1–4 hours as needed, with no absolute maximum daily dose—treatment continues until clinical improvement or escalation to advanced care is required. 1

Initial Intensive Phase (First Hour)

• Start with levosalbutamol 0.31–1.25 mg via nebulizer every 20 minutes for three consecutive doses (at 0,20, and 40 minutes) to achieve rapid bronchodilation during the period of maximal airway obstruction. 1

• The dose range allows weight-based titration: smaller children (6–7 years or <20 kg) typically receive 0.31 mg per dose, while larger children (8–11 years) receive 0.63–1.25 mg per dose. 1

• Deliver each dose in 3 mL of normal saline via oxygen-driven nebulizer to maintain SpO₂ >92%. 1, 2

• Measure peak expiratory flow (PEF) before treatment and again 15–30 minutes after the first dose to objectively guide subsequent management. 1, 2

Response-Based Dosing After the First Hour

Good Response (PEF >75% Predicted)

• Continue levosalbutamol 0.31–1.25 mg every 4–6 hours until PEF exceeds 75% of predicted and symptoms are minimal. 1, 2

Incomplete Response (PEF 50–75% Predicted)

• Maintain levosalbutamol 0.31–1.25 mg every 4 hours alongside systemic corticosteroids (prednisolone 1–2 mg/kg, maximum 40–60 mg daily). 1, 2
• Consider hospital admission if severe features persist after 1–2 hours of intensive treatment. 2

Poor Response (PEF <50% Predicted or Persistent Severe Features)

• Increase frequency to every 15–30 minutes or consider continuous nebulization at approximately 0.5 mg/kg/hour (practical maximum ~5 mg/hour for most children in this age range). 2, 3
• Add ipratropium bromide 100–250 µg to each nebulizer treatment and repeat every 6 hours until improvement begins. 2, 3
• Arrange immediate hospital admission. 2, 3

Practical Dosing Algorithm

Mild-to-Moderate Exacerbation (PEF 50–75%):

• 0.31–0.63 mg every 20 minutes × 3 doses, then every 4 hours 1

Severe Exacerbation (PEF <50%):

• 0.63–1.25 mg every 20 minutes × 3 doses, then every 1–2 hours or continuous nebulization 1, 2

Life-Threatening Features (PEF <33%, silent chest, altered mental status):

• 1.25 mg every 15–30 minutes or continuous nebulization, plus immediate hospital transfer 2, 3

Maximum Daily Dose Considerations

• There is no absolute maximum number of nebulizations or daily dose ceiling—treatment continues until clinical improvement occurs or escalation to intravenous therapy/intubation is required. 2

• The practical upper limit for frequent dosing is approximately 1.25 mg every 15–30 minutes for several hours, which may total 10–20 mg in the first 4–6 hours for refractory cases. 2

• Continuous nebulization at 0.5 mg/kg/hour (maximum ~5 mg/hour) is reserved for life-threatening exacerbations that fail intermittent therapy. 2, 3

Dose Equivalence to Racemic Albuterol

• Levosalbutamol is administered at approximately half the milligram dose of racemic albuterol to achieve comparable efficacy. 1, 3

• The 0.31–1.25 mg levosalbutamol range corresponds to 0.63–2.5 mg racemic albuterol, which is the standard pediatric dosing for this age group. 1

Adjunctive Therapies (Mandatory for Moderate-to-Severe Exacerbations)

• Systemic corticosteroids: Prednisolone 1–2 mg/kg orally (maximum 40–60 mg) immediately; continue for 3–5 days without taper. 2, 3, 4

• Ipratropium bromide: 100–250 µg added to each of the first three nebulizations, then every 6 hours until improvement. 2, 3

• Supplemental oxygen: High-flow via face mask to maintain SpO₂ >92%. 2, 3, 4

Safety Monitoring During High-Frequency Dosing

• Monitor for tachycardia (expected), tremor, and hypokalemia when levosalbutamol is given at frequent intervals or high cumulative doses. 1, 2

• Research evidence suggests levosalbutamol causes less tachycardia and hypokalemia than racemic albuterol at equivalent bronchodilator doses, though this advantage is modest. 5

• Tachycardia >140 beats/min is expected with β-agonist therapy; however, bradycardia is an ominous sign of impending respiratory arrest and mandates immediate ICU transfer. 2, 3

Critical Escalation Criteria (Immediate Hospital Transfer)

• PEF <33% predicted after initial therapy 2, 3
• Silent chest, cyanosis, or markedly feeble respiratory effort 2, 3
• Altered mental status (confusion, drowsiness, exhaustion) 2, 3
• Normal or elevated PaCO₂ ≥42 mmHg in a breathless child 2, 3
• Deteriorating PEF despite ongoing therapy 2, 3

When any of these criteria are met, consider intravenous magnesium sulfate 25–75 mg/kg (maximum 2 g) over 20 minutes, intravenous aminophylline 5 mg/kg over 20 minutes followed by 1 mg/kg/hour infusion, or transfer to intensive care for possible intubation. 2, 3

Common Pitfalls to Avoid

• Do not limit treatment to only three nebulizations—the initial three doses are the start of therapy, not the maximum; continue until clinical improvement or escalation is required. 2

• Do not delay systemic corticosteroids while "trying bronchodilators first"—both should be administered immediately, as delayed steroid therapy is a leading preventable cause of asthma mortality. 2, 3

• Never administer sedatives during an acute asthma attack; they are contraindicated and potentially fatal. 2, 3

• Do not rely solely on subjective assessment—always measure PEF or FEV₁ objectively to avoid underestimating severity. 2, 3

• Do not give a bolus of aminophylline to children already receiving oral theophylline due to toxicity risk. 2, 3

Discharge Criteria

• PEF ≥70–75% of predicted or personal best 2, 3
• Minimal or absent symptoms 2, 3
• Stable for 30–60 minutes after the last bronchodilator dose 2, 3
• Patient has been on discharge medications for ≥24 hours with verified inhaler technique 3, 4

Follow-Up Requirements

• Primary care follow-up within 1 week 3, 4
• Respiratory specialist clinic review within 4 weeks 3, 4
• Provide a written self-management plan with PEF zones and a personal peak-flow meter 2, 3