What are the guidelines for using 3% hypertonic saline solution via nebulizer in a patient with a respiratory condition, such as cystic fibrosis (CF) or chronic obstructive pulmonary disease (COPD), for loosening and clearing mucus from the airways?

3% Hypertonic Saline Nebulizer Therapy

Normal saline (0.9% sodium chloride) may be tried to loosen tenacious secretions at 5 ml six hourly, but there is no supporting scientific evidence for its routine use, and hypertonic saline (3%) is not recommended in the British Thoracic Society guidelines for standard nebulizer therapy. 1

Evidence-Based Indications

Cystic Fibrosis

• 3% hypertonic saline has demonstrated benefit in cystic fibrosis patients, with one study showing superior improvement in FEV₁ compared to 7% saline over 28 days 2
• The 3% concentration was better tolerated than 7% saline, with less immediate decrease in FEV₁ after inhalation 2
• Pretreatment with a β-agonist by hand-held inhaler or nebulizer is mandatory because there is a risk of bronchospasm 1

Bronchiolitis - NOT RECOMMENDED

• Nebulized 3% hypertonic saline should be avoided in acute bronchiolitis due to high rates of adverse events and lack of benefit 3
• A randomized controlled trial was halted early after severe adverse events occurred in 4 patients and parental requests for discontinuation in 2 patients due to child discomfort 3
• Minor adverse events occurred in 91.8% of children treated 3
• High aerosol output nebulizers were associated with 75% of severe adverse events 3

Mechanically Ventilated Patients - NOT RECOMMENDED

• Restricting 3% hypertonic saline use in mechanically ventilated patients according to AARC guidelines resulted in superior outcomes 4
• Patients who did not receive HTS/NAC had significantly more ventilator-free days at day 28 compared to those who received it 4
• The use of HTS/NAC in mechanically ventilated subjects does not appear efficacious and is both costly and time-consuming 4

Administration Protocol When Indicated

Equipment Setup

• Use jet nebulizers with a gas flow rate of 6-8 L/min to nebulize particles to 2-5 μm diameter for optimal small airway deposition 1, 5
• Drug volume should be 2-5 ml; if the nebulizer has a residual volume >1.0 ml, make up to a minimum of 4.0 ml 1, 5
• Never use water as a diluent - it may cause bronchoconstriction 1, 5

Pre-Treatment Requirements

• Administer a β-agonist bronchodilator before hypertonic saline to prevent bronchospasm 1
• This can be given via hand-held inhaler or nebulizer 1

Treatment Technique

• Position patient upright or in a chair 1
• Instruct patient to take normal steady breaths (tidal breathing) and not talk during nebulization 1
• Keep nebulizer upright throughout treatment 1
• Continue nebulization until about a minute after "spluttering" occurs, typically 5-10 minutes 1, 5
• Tap the nebulizer cup toward the end of treatment 1, 5

Post-Treatment Precautions

• Patients should not eat or drink for about an hour after treatment because of reduced sensitivity of the cough reflex 1

Safety Monitoring

For Sputum Induction (Special Use Case)

• When using 3% hypertonic saline for sputum induction, monitor oxygen saturation with transcutaneous oximetry during the procedure due to unpredictable arterial oxygen desaturation risk 5
• Use 20-30 mL with a high-output ultrasonic nebulizer 5

Adverse Event Profile

• When used without adjunctive bronchodilators in bronchiolitis, adverse event rate was 1.0% with bronchospasm rate of 0.3% 6
• However, the overall risk-benefit ratio in bronchiolitis remains unfavorable 3

Equipment Maintenance

• Clean nebulizer daily for regular use: disassemble, wash in warm water with detergent, rinse, and dry thoroughly 1, 5
• Run nebulizer empty briefly before next use 1, 5
• Replace disposable components (tubing, nebulizer cup, mask/mouthpiece) every 3-4 months 1, 5
• Service compressors annually 1, 5

Critical Pitfalls to Avoid

• Do not use in bronchiolitis - high adverse event rate with no proven benefit 3
• Do not use routinely in mechanically ventilated patients - associated with worse outcomes 4
• Never omit pre-treatment bronchodilator - risk of severe bronchospasm 1
• Never use water instead of saline - causes bronchoconstriction 1, 5
• Avoid high aerosol output nebulizers which are associated with increased adverse events 3