What is the first step in managing a non-expanding pneumothorax with negative suction?

Management of Non-Expanding Pneumothorax with Negative Suction

The first step in managing a non-expanding pneumothorax is to apply standard chest tube drainage without suction for 48 hours before considering negative suction pressure of -10 to -20 cm H₂O using a high volume, low pressure system. 1

Initial Management Protocol

1. Initial Chest Tube Placement

   • Insert a small-bore chest tube (≤14F) as recommended by the British Thoracic Society 1
   • Small-bore tubes cause less patient discomfort and fewer complications
   • Insertion technique: needle insertion with guidewire placement, dilation of tract, and tube insertion over guidewire

2. Standard Drainage Period

   • Allow 48 hours for spontaneous resolution with standard water seal drainage (no suction)
   • This waiting period is crucial to minimize the risk of re-expansion pulmonary edema, especially in primary pneumothoraces present for several days 1

3. Monitoring During Initial Period

   • Place patient in an area with specialized nursing experience
   • Monitor for complications including subcutaneous emphysema, re-expansion pulmonary edema, and hemodynamic instability
   • Perform chest X-rays to assess lung expansion

Application of Negative Suction

If the pneumothorax fails to resolve after 48 hours of standard drainage:

• Apply negative suction pressure of -10 to -20 cm H₂O 1
• Use only high volume, low pressure systems (critical for safety and efficacy)
• Avoid high pressure systems as they can cause:
  • Air stealing
  • Hypoxemia
  • Perpetuation of persistent air leaks

Common Pitfalls to Avoid

1. Premature Application of Suction

   • Applying suction before the 48-hour mark increases risk of re-expansion pulmonary edema 1
   • Particularly dangerous in pneumothoraces present for several days

2. Excessive Suction Pressure

   • Using pressure greater than -20 cm H₂O can worsen air leaks
   • Excessive suction has been associated with prolonged air leak due to alveolar over-distension 2

3. Using High Pressure Systems

   • These systems are associated with worse outcomes and more complications 1
   • Can perpetuate air leaks rather than resolve them

Ongoing Management and Evaluation

• Continue monitoring for complications (infection, tube blockage, tube displacement, subcutaneous emphysema)

• Patients with persistent air leaks have higher risk of complications:

  • Pneumonia (13.3% vs 4.9% in patients without persistent air leak)
  • Prolonged hospital stay (14.2 vs 7.1 days)
  • Increased chest tube duration (11.5 vs 3.4 days) 1

• Consider surgical referral if air leak persists:

  • After 5-7 days in patients without pre-existing lung disease
  • Earlier (2-4 days) in patients with underlying lung disease, large persistent air leak, or failure of lung to re-expand 1

Chest Tube Removal Criteria

Remove chest tube when all of the following are met:

• No air leak
• Drainage <100-150 mL per 24 hours for fluid
• Confirmed lung expansion on chest radiograph 1

By following this evidence-based approach with careful timing of negative suction application, you can optimize outcomes while minimizing complications in patients with non-expanding pneumothoraces.