When is nebulisation indicated and what is the recommended first‑line nebulised therapy for acute bronchospasm?

Nebulisation for Acute Bronchospasm

For acute bronchospasm, nebulised beta-agonists (salbutamol 2.5-5 mg or terbutaline) are the recommended first-line therapy, with ipratropium bromide 250-500 µg added for severe exacerbations or inadequate response to beta-agonists alone. 1, 2

Indications for Nebulisation

Nebulisers are indicated over handheld inhalers in specific clinical scenarios:

• Large drug doses are required for acute severe bronchospasm 1
• Coordinated breathing is impaired in acutely ill patients with severe asthma or COPD exacerbations 1
• Handheld inhalers have proven ineffective despite proper technique in chronic lung disease 1
• Patients cannot generate adequate inspiratory flow to use dry powder inhalers effectively 3
• Cognitive or neuromuscular impairments prevent proper inhaler technique 3

First-Line Nebulised Therapy Protocol

Beta-Agonist Monotherapy

• Salbutamol 2.5-5 mg or terbutaline 5-10 mg nebulised over 10 minutes 1
• Driven by oxygen at 6-8 L/min in acute severe asthma due to hypoxia risk 1
• Driven by compressed air in COPD to avoid CO₂ retention 1

Combination Therapy for Severe Cases

• Add ipratropium bromide 250-500 µg to beta-agonist for severe exacerbations 1, 2
• DuoNeb (ipratropium 0.5 mg + albuterol 2.5 mg in 3 mL) can be administered every 20 minutes for up to 3 doses initially, then every 6-8 hours 2
• Maximum frequency is four times daily for maintenance 2

Technical Specifications

Gas Flow and Volume

• Flow rate of 6-8 L/min produces optimal particle size (2-5 µm) for small airway deposition 1
• Starting volume of 2-2.5 mL is sufficient for most ward nebulisers that leave 0.5 mL residual 1
• Nebulisation time of 10 minutes is adequate for bronchodilators 1

Interface Selection

• Masks are preferred for acutely ill patients who find holding the nebuliser tiring 1
• Mouthpieces should be used for anticholinergics in patients at risk for glaucoma exacerbation 1

Assessment of Response

Objective Criteria

• Peak flow improvement >15% indicates beneficial response and justifies continued therapy 4
• Subjective improvement with <15% peak flow change requires clinical judgment but may warrant continuation 1

Reassessment Strategy

• Formal assessment over 1-2 weeks with twice-daily peak flow and symptom scores for each drug or combination 1
• First dose under supervision with formal instruction in equipment use 2
• Regular follow-up at respiratory clinic for patients on long-term nebuliser therapy 2

Critical Pitfalls to Avoid

Oxygen vs. Air Selection

• Never use oxygen routinely in COPD as it risks CO₂ retention in susceptible patients 1
• Always use oxygen in acute severe asthma due to hypoxia 1
• Low-flow oxygen via nasal cannulae can be given simultaneously while nebulising with air if needed 1

Elderly Patient Considerations

• Beta-agonist response declines faster than anticholinergic response with age, favoring earlier anticholinergic use 1
• ECG monitoring may be needed for first dose in elderly patients with ischemic heart disease 1
• Use mouthpiece rather than mask for high-dose anticholinergics to prevent acute glaucoma 1

Dosing Errors

• Continuous nebulisation at 7.5 mg/hr albuterol shows no advantage over higher doses (15 mg/hr) in moderate-severe bronchospasm 5
• Do not use water as diluent as it causes bronchoconstriction when nebulised 1

Alternative to Nebulisation

MDI with spacer device delivers equivalent therapy to nebulisation in many situations, using lower medication doses and faster administration time 4, 6. For tracheostomy patients, a 750 mL spacer with appropriately sized face mask can be placed over the tracheal stoma 4.