Can a 4‑month‑old infant be safely nebulised with sterile normal 0.9% NaCl (sodium chloride) saline?

Nebulisation with Normal Saline in a 4-Month-Old Infant

Yes, you can safely nebulise a 4-month-old infant with sterile 0.9% normal saline (sodium chloride), as this is explicitly recognized by the British Thoracic Society as an appropriate nebulisation solution, particularly when used to assist physiotherapy or as a diluent for bronchodilator medications. 1

Key Safety Requirements

Critical Safety Points

• Never use water for nebulisation – water can cause bronchoconstriction when nebulised and should never be used as a diluent 1, 2
• Use only sterile 0.9% sodium chloride solution 1
• For infants, masks with straps are preferred over mouthpieces due to coordination difficulties 1

Proper Administration Technique for Infants

Equipment Setup:

• Use a jet nebuliser with gas flow rate of 6-8 L/min to produce particles of 2-5 μm diameter for optimal small airway deposition 1, 2
• Fill volume should be 2.0-4.5 mL of 0.9% saline 1, 2
• If the nebuliser has a residual volume >1.0 mL, use a minimum fill volume of 4.0 mL 2

During Treatment:

• Position the infant upright or in a sitting position 3
• Use a tight-fitting face mask 1
• The breathing pattern is particularly important in infants – steady normal breathing interspersed with occasional deep breaths is optimal 1
• Nebulisation typically takes 5-10 minutes 2
• Continue until about a minute after "spluttering" occurs rather than waiting for complete dryness 2

Clinical Context Considerations

When Normal Saline is Appropriate:

• To assist with physiotherapy and mucus clearance 1
• As a diluent when mixing with bronchodilators (β-agonists like salbutamol can be mixed with saline to make up to 4.5 mL total volume) 2
• When inhalers with spacer and mask are not working effectively in infants 1

Important Limitation:

The British Thoracic Society notes that normal saline (0.9%) has no supporting scientific evidence for routine therapeutic use on its own 3. If the clinical goal is to treat bronchiolitis or actively mobilize mucus plugs, hypertonic saline (3%) may be more effective than normal saline, though this requires pre-treatment with a bronchodilator 4, 3, 5.

Equipment Maintenance for Safety

Daily cleaning is essential:

• Disassemble the nebuliser after each use 2, 3
• Wash in warm water with detergent 1, 2, 3
• Rinse thoroughly and dry completely 2, 3
• Run the nebuliser empty briefly before next use to clear moisture 2
• Replace disposable components every 3-4 months 2, 3

Common Pitfalls to Avoid

• Do not use tap water or distilled water – only sterile 0.9% sodium chloride 1, 2
• Do not use oxygen as the driving gas unless specifically prescribed (use air for routine nebulisation in infants) 1
• Do not allow multi-dose bottles to be shared between patients due to contamination risk 6
• Ensure the mask fits tightly to the infant's face for effective delivery 1