What is the recommended duration for applying negative suction in a non-expanding pneumothorax?

Recommended Duration of Negative Suction for Non-Expanding Pneumothorax

Negative suction pressure of -10 to -20 cm H₂O should only be applied after 48 hours of standard chest tube drainage for non-expanding pneumothoraces, using a high volume, low pressure system. 1

Suction Application Protocol

Initial Management

• First 48 hours: Use standard chest tube drainage without suction
  • This delay helps minimize the risk of re-expansion pulmonary edema, especially in primary pneumothoraces that have been present for several days 1
  • Standard chest tube drainage alone is successful in many cases, making immediate suction unnecessary

When to Apply Suction

• Apply suction only after 48 hours if:
  • The pneumothorax is slow to re-expand
  • Standard drainage has failed to achieve lung re-expansion 2

Suction Parameters

• Pressure: -10 to -20 cm H₂O (safe and effective range)
• System type: High volume, low pressure systems only (e.g., Vernon-Thompson pump or wall suction with pressure-reducing adaptor) 2, 1
• Avoid:
  • High pressure, high volume suction (can cause air stealing, hypoxemia, or perpetuation of persistent air leaks)
  • High pressure, low volume systems 2

Duration of Suction and Surgical Referral Timing

For Patients Without Pre-existing Lung Disease

• Continue suction for up to 5-7 days
• If air leak persists after 5-7 days, refer for surgical evaluation 2, 1

For Patients With Underlying Lung Disease

• Consider earlier surgical referral (2-4 days) if:
  • Large persistent air leak continues
  • Lung fails to re-expand
  • Underlying lung disease is present 2, 1

Patient Monitoring and Care

• Place patients on suction in an area with specialized nursing experience 2
• Monitor closely for complications including:
  • Re-expansion pulmonary edema (RPO)
  • Subcutaneous emphysema
  • Persistent air leak
  • Hemodynamic instability 1

Important Considerations and Caveats

• The application of suction too early (before 48 hours) may precipitate re-expansion pulmonary edema, particularly in primary pneumothoraces that have been present for several days 2
• Recent research has not demonstrated significant advantages of negative pleural suction over conventional underwater seal drainage in terms of duration of chest tube placement or length of hospital stay 3
• The arbitrary 5-day cut-off for surgical intervention has been challenged and remains contentious, with some evidence suggesting that earlier intervention may be beneficial in certain cases 2
• For patients who are either unwilling or unable to undergo surgery, chemical pleurodesis can be considered as an alternative management strategy, but should only be performed by respiratory specialists 2, 1

Removal Criteria

• Chest tube can be removed when:
  • No air leak is present
  • Drainage is less than 100-150 mL per 24 hours for fluid
  • Lung expansion is confirmed on chest radiograph 1

While some older studies have questioned the benefits of suction 4, the most recent and comprehensive guidelines from the British Thoracic Society and other expert sources consistently recommend the approach outlined above for non-expanding pneumothoraces.