When should a patient with a pneumothorax and a chest tube to gravity be placed on suction?

When to Place a Chest Tube on Suction for Pneumothorax

Apply suction if the lung fails to reexpand with water seal drainage alone, or after 48 hours of persistent air leak or incomplete lung reexpansion. 1

Initial Management Strategy

Start with water seal (gravity) drainage without suction for most patients with pneumothorax after chest tube insertion. 1 This approach is supported by good consensus from the American College of Chest Physicians and is the preferred initial strategy unless specific high-risk features are present. 1

Specific Indications to Apply Suction

Immediate or Early Suction Application

Apply suction immediately or early if:

• The lung fails to reexpand quickly with water seal drainage alone 1
• Patient is clinically unstable with a large pneumothorax (≥3 cm apex-to-cupola distance) 1
• Large air leak is present (greater than expiratory grade 3) 2, 3
• Patient requires positive-pressure ventilation or has anticipated bronchopleural fistula 1, 4
• Subcutaneous emphysema develops or pneumothorax is enlarging and causing hypoxia 2, 3

Delayed Suction Application (After 48 Hours)

The 48-hour rule is critical: If after 48 hours there is persistent air leak or failure of the pneumothorax to reexpand, suction should be applied. 1 This timing is based on British Thoracic Society guidelines and helps avoid complications like re-expansion pulmonary edema that can occur with premature suction application. 1

Technical Specifications for Suction

When suction is required:

• Use high-volume, low-pressure suction systems (−10 to −20 cm H₂O) 1
• Avoid high-pressure systems as they can cause air stealing, hypoxemia, or perpetuate persistent air leaks 1
• Ensure specialist nursing experience is available when managing patients on suction 1

Alternative Approach: Immediate Suction Option

While water seal is preferred initially, some consensus exists for applying suction immediately after chest tube placement for all patients managed with a water seal system, though this is a weaker recommendation. 1 This approach may be considered in unstable patients but carries risk of re-expansion pulmonary edema if the pneumothorax has been present for several days. 1

Clinical Decision Algorithm

1. Insert chest tube → Connect to water seal (gravity) initially 1
2. Assess clinical stability and pneumothorax size 1
3. If unstable, large leak, or ventilated → Apply suction immediately 1, 4, 2
4. If stable → Observe on water seal for 48 hours 1
5. At 48 hours: If persistent air leak or incomplete reexpansion → Apply suction 1
6. If pneumothorax enlarges or subcutaneous emphysema develops → Apply suction regardless of timing 2, 3

Important Caveats

• Never clamp a bubbling chest tube as this may cause tension pneumothorax, a potentially fatal complication 5, 4
• Patients with underlying lung disease (COPD, secondary pneumothorax) may require earlier suction application (2-4 days rather than 5-7 days) due to higher risk of persistent air leak 1
• Pneumothorax size >8 cm is a predictor of failing water seal and may warrant earlier suction 3
• Refer to respiratory specialist if pneumothorax fails to respond within 48 hours or if persistent air leak exceeds 48 hours 1