What is the appropriate method and dosing for administering salbutamol by nebulisation in adults and children, including equipment, preparation, administration technique, and safety precautions?

How to Administer Salbutamol Nebulization

Administer salbutamol 2.5–5 mg nebulized in adults and 0.15 mg/kg (minimum 2.5 mg) in children, diluted to a minimum of 3–4 mL with normal saline, driven by oxygen at 6–8 L/min for acute asthma or compressed air for COPD, repeated every 20 minutes for three doses, then every 4–6 hours as needed. 1, 2, 3

Equipment Setup and Preparation

Nebulizer Configuration

• Use a jet nebulizer with either a mouthpiece or face mask depending on patient preference and clinical status 1
• Mouthpieces are theoretically superior as they avoid nasal deposition, though breathless patients often prefer face masks and clinical outcomes are equivalent 1
• Ensure the nebulizer system has a residual volume <1.0 mL; if residual volume exceeds this, dilute the drug to a minimum total volume of 4 mL with 0.9% sodium chloride 1

Driving Gas Selection

• For acute asthma: use oxygen at 6–8 L/min as the driving gas to simultaneously treat bronchospasm and hypoxemia 1, 3
• For COPD exacerbations: use compressed air (not oxygen) to prevent worsening CO₂ retention and respiratory acidosis 1, 3
• If COPD patients require supplemental oxygen during air-driven nebulization, provide low-flow oxygen (1–4 L/min) via nasal cannulae simultaneously 3, 4

Dosing Protocols

Adults

Acute Asthma

• Initial dose: 2.5–5 mg salbutamol (or 5–10 mg terbutaline) 1
• Repeat every 20 minutes for the first hour (three doses total) 1, 3
• After initial three doses, continue every 4–6 hours as needed based on clinical response 1
• Add ipratropium bromide 500 µg to each nebulization if poor initial response or severe presentation 1

COPD Exacerbations

• Dose: 2.5–5 mg salbutamol (or 5–10 mg terbutaline) 1
• Administer every 4–6 hours 1
• Adding ipratropium provides no additional benefit in acute COPD exacerbations (unlike in asthma) 1

Children

Pediatric Dosing

• Weight-based: 0.15 mg/kg salbutamol (or 0.3 mg/kg terbutaline) with a mandatory minimum of 2.5 mg regardless of weight 1, 2
• For acute severe asthma: repeat every 20 minutes for three doses, then every 1–4 hours as needed 1, 2
• Add ipratropium bromide 250 µg (half the adult dose) if moderate-to-severe distress after initial treatment 1, 2

Alternative MDI-Spacer Approach (Preferred When Feasible)

• MDI with spacer and face mask is the recommended first-line delivery method for infants and children, offering comparable efficacy while being more economical 2
• Give 2 puffs (180 µg total) via MDI-spacer-mask every 20 minutes for three doses; up to 20 puffs cumulative may be used in severe cases 2

Administration Technique

Nebulization Process

• Nebulize until approximately one minute after "spluttering" occurs, typically 5–10 minutes total 1
• Never use "dryness" as an endpoint for stopping treatment 1
• Instruct patients to tap the nebulizer cup toward the end of treatment to mobilize remaining medication 1
• Set an upper time limit for treatment (typically 10 minutes maximum) 1

Patient Positioning and Interface

• Use face masks for acutely breathless patients, infants, and those unable to hold a mouthpiece 3
• Use mouthpieces when administering ipratropium to elderly patients to avoid ocular complications and glaucoma risk 1, 3

Monitoring and Safety

Clinical Assessment

• Measure peak expiratory flow before and after each treatment 3
• Monitor for β-adrenergic side effects: tachycardia, tremor, palpitations (though uncommon with inhaled therapy) 2, 3
• First treatment should always be supervised, especially in elderly patients who may develop angina 1

Escalation Criteria

• Lack of response to repeated nebulized therapy indicates need for senior clinician review and consideration of additional interventions 1
• For refractory severe asthma, consider continuous nebulization at 0.5 mg/kg/hour (maximum 10–15 mg/hour) in intensive care settings 3, 4
• Add systemic corticosteroids (oral prednisolone 2 mg/kg/day for 3 days in children, maximum 40 mg/day) for moderate-to-severe exacerbations 2

Critical Pitfalls to Avoid

• Never drive nebulizers with oxygen in COPD patients with CO₂ retention without monitoring arterial blood gases 3, 4
• Never use compressed air or room air as driving gas in hypoxic asthma patients; always use oxygen at 6–8 L/min 2
• Do not continue nebulized therapy indefinitely without reassessment; transition to hand-held inhalers within 24–48 hours once stable to permit earlier discharge 1, 3
• Avoid using face masks with ipratropium in elderly patients due to glaucoma risk; use mouthpiece instead 1

Equipment Maintenance

• Change disposable components (tubing, nebulizer cup, mask/mouthpiece) every 3–4 months 1
• Disassemble, wash, and dry nebulizers daily for bronchodilator therapy 3
• Service compressors annually 1