When should suction be applied to a chest drain?

When to Apply Suction to a Chest Drain

Suction should not be applied immediately after chest drain insertion; instead, wait 48 hours and only apply suction if there is a persistent air leak (continued bubbling) or failure of the lung to re-expand on chest radiograph. 1

Initial Management: No Suction

• Do not apply suction routinely at the time of chest drain insertion – there is no evidence supporting immediate suction use in spontaneous pneumothorax management. 1
• Allow the chest drain to function on underwater seal (water seal) drainage alone for the first 48 hours. 1
• Monitor for respiratory swing in the drainage system, which confirms proper tube positioning and patency. 2

Critical Safety Warning

• Applying suction too early risks re-expansion pulmonary edema (RPO), particularly in primary pneumothorax that may have been present for several days before treatment. 1

Indications to Add Suction After 48 Hours

Apply suction only when one or both of the following conditions persist after 48 hours:

• Persistent air leak: Continued air bubbling through the chest tube at 48 hours post-insertion. 1
• Failure of lung re-expansion: Incomplete lung expansion visible on chest radiograph despite adequate drainage. 1

Technical Specifications for Suction

When suction is indicated, use specific parameters:

• High volume, low pressure systems only: Apply -10 to -20 cm H₂O suction. 1
• Use devices such as Vernon-Thompson pump or wall suction with pressure-reducing adaptor. 1
• The system should have capacity for air flow volume of 15-20 L/min. 1

Systems to Avoid

• Never use high pressure, high volume systems – these generate excessive air flow that can cause air stealing, hypoxemia, or perpetuate persistent air leaks. 1
• Avoid high pressure, low volume systems as well. 1

Required Care Environment

• Patients requiring suction must be managed only in specialized lung units with experienced medical and nursing staff trained in chest drain management. 1
• This specialized setting is essential for safe monitoring and management of potential complications. 1

Escalation Timeline

If problems persist despite suction:

• Refer to respiratory specialist if pneumothorax fails to respond within 48 hours or if persistent air leak continues. 1, 3
• Surgical referral timing:
  • For patients without underlying lung disease: refer at 5-7 days of persistent air leak. 1
  • For patients with underlying lung disease, large persistent air leak, or failure of lung re-expansion: consider earlier referral at 2-4 days. 1, 3
  • Request thoracic surgical opinion at 3-5 days for persistent air leak or failure of lung re-expansion. 1, 3

Special Considerations

Underlying Lung Disease

• Patients with emphysema or fibrosis typically have longer resolution times (median 19 days vs 8 days without lung disease). 1
• These patients require more aggressive early specialist involvement. 3

Post-Surgical Context

• After lobectomy, higher suction levels (-20 cm H₂O) increase fluid output compared to lower levels (-5 cm H₂O), which may delay drain removal. 4
• In post-lobectomy patients, routine suction is not necessary and water seal alone is often sufficient. 5
• Suction may be useful for persistent pneumothorax with adequate air entry and clear airways, but provides no benefit when the lung is already expanded. 5

Common Pitfalls to Avoid

• Never clamp a bubbling chest drain – this risks tension pneumothorax. 2
• Do not drain more than 1-1.5 liters at one time or faster than 500 mL/hour to prevent re-expansion pulmonary edema. 2
• Ensure the drainage bottle remains below chest level at all times to prevent backflow. 2