What is rescue nebulization?

What is Rescue Nebulization

Rescue nebulization refers to the emergency or as-needed administration of bronchodilator medications via nebulizer to rapidly relieve acute bronchospasm in patients experiencing severe respiratory distress from asthma or COPD exacerbations. 1, 2

Core Definition and Purpose

Rescue nebulization is a drug delivery method that converts liquid bronchodilator medications into a fine mist of particles (2-5 μm diameter) that can reach the small airways and alveoli. 1 This delivery system is specifically designed for situations where:

• Large drug doses are needed urgently 1
• Coordinated breathing is difficult in acutely ill patients with severe asthma or COPD exacerbations 1
• Hand-held inhalers have proven ineffective or cannot be used properly due to the severity of respiratory distress 1, 2

Clinical Indications for Rescue Nebulization

Acute Severe Asthma in Adults

Rescue nebulization is indicated when patients present with: 1

• Inability to complete sentences in one breath
• Respiratory rate ≥25/min
• Heart rate ≥110/min
• Peak expiratory flow ≤50% of predicted or best value

Acute Severe Asthma in Children

Rescue nebulization is indicated when pediatric patients present with: 1, 2

• Inability to speak or feed
• Respiratory rate >50/min
• Heart rate >140/min
• Peak expiratory flow <50% of predicted value

COPD Exacerbations

Rescue nebulization is appropriate for more severe COPD exacerbations when hand-held inhalers are insufficient. 1

Standard Rescue Nebulization Protocol

First-Line Treatment

For adults with acute severe asthma or COPD: 1

• Nebulized β-agonist: salbutamol 5 mg or terbutaline 10 mg
• Repeat every 4-6 hours if improving

For children with acute severe asthma: 1, 3

• Salbutamol 5 mg (or 0.15 mg/kg) or terbutaline 10 mg (or 0.3 mg/kg)
• Repeat every 1-4 hours if improving

Poor Response Protocol

If inadequate response to initial β-agonist treatment: 1

• Add ipratropium bromide 500 μg to the β-agonist
• Repeat combined nebulization
• Consider hospital admission

For children with poor response: 3

• Repeat at 30 minutes after adding ipratropium bromide 250 μg
• Continue hourly and consider hospital transfer

Technical Parameters

Gas Flow and Driving Source

• Flow rate: 6-8 L/min is required to generate appropriate particle size 1, 2
• In acute severe asthma: use oxygen as the driving gas when possible, as patients are hypoxic 1
• In COPD with CO2 retention: use compressed air to avoid worsening hypercapnia 1, 2

Volume and Duration

• Liquid volume: 2-4.5 mL (use 0.9% saline to complete volume if needed, never water) 1, 2
• Treatment duration: approximately 10 minutes for bronchodilators 1, 2
• Continue until about one minute after "spluttering" occurs 1

Critical Safety Considerations

Oxygen vs. Air

A common and dangerous pitfall: Using oxygen to drive nebulizers in COPD patients with CO2 retention can worsen respiratory acidosis. 1, 2 If arterial blood gases show CO2 retention and acidosis, or if gas tensions cannot be measured (e.g., in general practice), the nebulizer must be driven by air, not oxygen. 1

Never Use Water

Water should never be used as a diluent because it causes bronchoconstriction when nebulized. 1, 2 Always use 0.9% sodium chloride solution. 2, 3

Delivery Interface

• Masks are preferred for acutely ill patients when holding the nebulizer is exhausting, and for babies/young children 1, 3
• Mouthpieces should be used for nebulized steroids (to prevent facial deposition) and for anticholinergics in patients at risk for glaucoma 1, 3

Distinction from Maintenance Nebulization

Rescue nebulization differs fundamentally from long-term maintenance nebulizer therapy. 1 While maintenance therapy requires specialist assessment and regular scheduled treatments, rescue nebulization is:

• Used for acute emergencies rather than chronic daily management 1, 2
• Administered as needed based on symptom severity 4
• Intended for immediate bronchodilation rather than long-term disease control 5

When to Escalate Care

Seek immediate medical attention if: 1

• Life-threatening features develop (PEF <33% predicted, silent chest, cyanosis, bradycardia, exhaustion, confusion)
• Poor response to repeated rescue nebulizations
• Previously effective dosage regimen fails to provide usual relief 4