What is the recommended nebulised salbutamol dose for acute bronchospasm in adults, children over 12 years, children 2–12 years, and infants under 2 years?

Salbutamol Nebulizer Dosing for Acute Bronchospasm

For acute bronchospasm, administer salbutamol 2.5–5 mg via nebulizer every 20 minutes for three doses in the first hour, then every 1–4 hours as needed based on clinical response. 1

Adult Dosing (≥12 years)

• Initial treatment: Give 2.5–5 mg salbutamol nebulized every 20 minutes for three consecutive doses during the first hour 2, 1
• Maintenance: Continue 2.5–5 mg every 1–4 hours as needed, adjusting frequency based on symptom control 2, 1
• Severe exacerbations: Use 5 mg doses and consider continuous nebulization at 10–15 mg/hour for life-threatening cases or inadequate response to intermittent dosing 1
• Moderate exacerbations: 2.5–5 mg is appropriate, with the option to use either dose depending on severity 2

Children 2–12 Years

• Weight-based dosing: Administer 0.15 mg/kg (minimum 2.5 mg) every 20 minutes for three doses, then every 1–4 hours as needed 2, 1
• Fixed dosing alternative: A fixed dose of 2.5 mg is equally effective as weight-based dosing (0.1 mg/kg) for mild-to-moderate asthma in children aged 4–12 years 3
• Standard approach: Use 5 mg or 0.15 mg/kg for acute symptoms, repeating every 20–30 minutes in the first hour for severe cases 2, 4

Infants Under 2 Years

• Recommended dose: 0.15 mg/kg (minimum 2.5 mg) every 20 minutes for three doses initially 1
• Maintenance: Continue every 1–4 hours as needed based on clinical response 1
• Special consideration: Use a nebulizer with face mask if the infant cannot tolerate a spacer device 2

Critical Administration Details

Nebulizer Preparation

• Dilute each dose in at least 3 mL of normal saline to ensure optimal aerosol generation 1
• Use oxygen as the driving gas at 6–8 L/min flow rate whenever possible for improved drug delivery and oxygenation 1
• Exception for COPD: In patients with severe COPD at risk for CO₂ retention, use compressed air instead of oxygen to avoid worsening hypercapnia 2, 1

Adjunctive Therapy

• Add ipratropium bromide 0.25–0.5 mg to each of the first three salbutamol doses for moderate-to-severe exacerbations 2, 1
• Administer systemic corticosteroids early (prednisolone 30 mg/day for adults or 1–2 mg/kg/day for children, maximum 60 mg/day) for moderate-to-severe cases 2, 1

Monitoring and Safety

Essential Monitoring Parameters

• Watch for tachycardia, tremor, and hypokalemia, especially with frequent or high-dose administration 1
• Reassess after each treatment cycle for signs of impending respiratory failure: inability to speak, altered mental status, intercostal retractions, worsening fatigue 1
• Cardiovascular effects are minimal at standard doses (2.5 mg); only doses 5–10 times higher (12.5–25 mg) cause clinically significant tachycardia (20–30 beat increase) 5

Response Assessment

• Measure clinical score, oxygen saturation, and peak flow before treatment and at 15 and 30 minutes after each dose 3
• Continue nebulized treatments for 24–48 hours or until peak flow >75% predicted and diurnal variability <25% 2
• Transition to MDI with spacer 24–48 hours before discharge once the patient is clinically improving 2

Alternative Delivery Method

For mild-to-moderate exacerbations, an MDI with spacer (4–8 puffs every 20 minutes for three doses) is equally effective as nebulization when proper technique is used. 1, 4 However, nebulized therapy remains preferred for severe exacerbations and in emergency settings where simultaneous oxygen delivery is needed. 1

Common Pitfalls to Avoid

• Do not use inadequate doses: Single 2.5 mg doses or infrequent dosing are insufficient for acute bronchospasm 1
• Do not delay corticosteroids: Early systemic steroid administration is critical for moderate-to-severe exacerbations 2, 1
• Do not withhold treatment for tachycardia or cardiac history: Salbutamol at standard doses does not induce severe arrhythmias, even in high-risk populations 5
• Do not continue ipratropium beyond initial stabilization: Additional benefit has not been demonstrated once the patient is hospitalized 1