What is the recommended nebulisation protocol for acute respiratory symptoms?

Nebulisation Protocol for Acute Respiratory Symptoms

For acute severe asthma, administer nebulised salbutamol 5 mg (or terbutaline 10 mg) driven by oxygen at 6-8 L/min, repeated every 20-30 minutes for the first hour, then 4-6 hourly; add ipratropium bromide 500 µg if poor initial response. 1

Equipment Setup

Driving Gas Selection

• Use oxygen as the driving gas only in acute severe asthma because these patients are hypoxic and require simultaneous treatment of both bronchospasm and hypoxemia 1, 2
• Use compressed air (not oxygen) for COPD exacerbations to prevent worsening carbon dioxide retention and acidosis 1, 3
• If supplemental oxygen is needed during air-driven nebulisation, administer low-flow oxygen (4 L/min) via nasal cannulae simultaneously 1, 2

Flow Rate and Equipment

• Set gas flow rate at 6-8 L/min to generate particles of 2-5 µm diameter for optimal small airway deposition 1, 2
• Use jet nebulisers with electrical compressors (more accurate and cost-effective than cylinder flow meters) 1, 2
• Fill nebuliser chamber with 2.0-4.5 ml total volume; if residual volume >1.0 ml, make up drug volume to minimum 4.0 ml with 0.9% sodium chloride (never water, which causes bronchoconstriction) 1

Drug Dosing by Condition

Acute Severe Asthma (Adults)

Severity criteria: Cannot complete sentences, respiratory rate ≥25/min, heart rate ≥110/min, peak flow ≤50% predicted 1

Initial treatment:

• Salbutamol 5 mg OR terbutaline 10 mg via oxygen-driven nebuliser 1, 3
• Repeat every 20-30 minutes for first hour if improving 1
• Add ipratropium bromide 500 µg if poor response after first dose 1, 3
• Combined therapy (salbutamol + ipratropium) provides 16-32% greater peak flow improvement than salbutamol alone 4, 5

Ongoing treatment:

• Continue 4-6 hourly until peak flow >75% predicted and diurnal variability <25% 1
• For severe cases, frequent dosing of 0.3 mg/kg salbutamol hourly (maximum 10 mg/hour) or 1-3 mg/hour terbutaline may be used 1

Acute Severe Asthma (Children)

Severity criteria: Cannot talk or feed, respiratory rate >50/min, heart rate >140/min, peak flow <50% predicted 1

• Salbutamol 5 mg (or 0.15 mg/kg) OR terbutaline 10 mg (or 0.3 mg/kg) 1
• Repeat 1-4 hourly if improving 1
• If no improvement at 30 minutes, add ipratropium bromide 250 µg and continue hourly 1

COPD Exacerbations

Mild exacerbations:

• Use hand-held inhaler with salbutamol 200-400 µg or terbutaline 500-1000 µg 1

Moderate-to-severe exacerbations:

• Salbutamol 2.5-5 mg OR terbutaline 5-10 mg OR ipratropium bromide 500 µg 1, 3
• Give 4-6 hourly for 24-48 hours or until clinical improvement 1
• Use combined therapy (β-agonist 2.5-10 mg + ipratropium 250-500 µg) in severe cases or poor response to monotherapy 1
• Critical: Drive nebuliser with air if patient has carbon dioxide retention/acidosis or if blood gases cannot be measured 1, 3

Administration Technique

Interface Selection

Use masks for:

• Acutely ill patients (too breathless to hold mouthpiece) 1
• Babies and young children with poor coordination 1

Use mouthpieces for:

• Nebulised steroids (prevents facial deposition) 1
• Nebulised antibiotics (allows filter attachment) 1
• Anticholinergics in patients at risk for glaucoma 1, 3
• When using ipratropium, ensure tight-fitting mask or mouthpiece to prevent eye contact causing pupil dilation or glaucoma precipitation 3, 6

Treatment Duration

• Bronchodilators: 10 minutes should be sufficient 1
• Continue until approximately 1 minute after "spluttering" occurs (5-15 minutes typical) 1, 6
• Tap nebuliser cup toward end of treatment to mobilize remaining solution 1
• Do not use "dryness" as endpoint; specify upper time limit 1

Drug Compatibility and Mixing

• Ipratropium bromide can be mixed with salbutamol or terbutaline in the nebuliser if used within 1 hour 6
• Do not mix with other drugs; stability and safety not established 6
• Never use water as diluent—only 0.9% sodium chloride 1, 2

Critical Safety Considerations

Common Pitfalls to Avoid

• Never use oxygen-driven nebulisers routinely in COPD due to carbon dioxide retention risk 1, 2
• Measure arterial blood gases in hospitalized patients; if CO₂ retention present, use air-driven nebulisation 1
• Continuous nebulisation shows no advantage over intermittent dosing in acute severe asthma 7
• MDI with spacer may be equally effective as nebulisation but is not yet widely adopted in acute settings 1, 8

Monitoring Response

• Reassess at 15,30,60,120,180, and 240 minutes 4
• Failure to respond or shortened duration of effect is a warning sign requiring urgent medical attention 1
• Switch to hand-held inhaler 24-48 hours before hospital discharge 1

Equipment Maintenance

• Wash mouthpiece/mask and nebuliser chamber after every use (minimum once daily) with warm water and detergent, rinse thoroughly, and dry completely 1
• Change disposable components (tubing, nebuliser cup, mask/mouthpiece) every 3 months 1, 3
• Service compressors annually 1
• For antibiotics, use separate equipment and change every 3 months; use filters to prevent environmental contamination 1, 3