What is the role of negative suction in the management of a non-expanding pneumothorax with a chest tube (chest drainage tube)?

Role of Negative Suction in Non-Expanding Pneumothorax Management

Negative suction should be applied to a water-seal device if the lung fails to reexpand quickly after chest tube placement for a non-expanding pneumothorax. 1

Initial Management Approach

When managing a non-expanding pneumothorax with a chest tube in place:

1. First 48 hours:

   • Initially use water seal drainage without suction 1
   • Monitor for lung re-expansion with serial chest radiographs
   • Ensure proper chest tube function (check for kinking or blockage) 2

2. After 48 hours if pneumothorax persists:

   • Apply negative suction to the water-seal device 1
   • Use high volume, low pressure suction (-10 to -20 cm H2O) 1
   • Avoid high pressure systems which can cause air stealing or perpetuate air leaks 1

Suction Parameters and Monitoring

• Recommended suction level: -10 to -20 cm H2O 1
• System type: High volume, low pressure systems (e.g., Vernon-Thompson pump or wall suction with pressure adaptor) 1
• Air flow capacity: System should handle 15-20 L/min 1
• Location: Patients requiring suction should be managed in specialized lung units with appropriate nursing expertise 1

Important Cautions

• Avoid immediate suction: Applying suction too early after chest tube insertion, particularly in primary pneumothorax present for several days, may precipitate re-expansion pulmonary oedema (RPO) 1, 3
• Monitor for complications: Watch for subcutaneous emphysema, which may require additional intervention if severe 4
• Risk factors for re-expansion pulmonary edema: Longer duration of lung collapse (>7 days) and larger pneumothorax size significantly increase risk 3

Persistent Non-Expansion Protocol

If pneumothorax persists despite suction:

1. Days 3-5: Seek thoracic surgical opinion for persistent air leak or failure of lung re-expansion 1
2. Days 5-7: Consider surgical intervention for patients without pre-existing lung disease 1
3. Days 2-4: Consider earlier surgical referral for patients with underlying lung disease, large persistent air leak, or failure of lung re-expansion 1

Special Considerations

• Outpatient management: For stable patients with small-caliber chest tubes and Heimlich valves, outpatient management may be appropriate, though patients with emphysema are more likely to require prolonged drainage or additional interventions 5
• Chemical pleurodesis: Consider only if the patient is unwilling or unable to undergo surgery for persistent pneumothorax 1
• Surgical options: For persistent air leaks beyond 4 days, thoracoscopy is the preferred surgical approach for air leak closure and pleurodesis 1

The evidence strongly supports a stepwise approach to managing non-expanding pneumothoraces, with suction playing a crucial role when initial water seal drainage fails to achieve lung re-expansion, while being mindful of the timing of suction application to minimize complications.