Does supplemental O2 (oxygen) help resolve pneumothorax?

Supplemental Oxygen for Pneumothorax Resolution

Supplemental oxygen therapy accelerates the resolution of pneumothorax and should be used in patients with pneumothorax who require observation rather than immediate drainage. This recommendation is supported by the British Thoracic Society (BTS) guidelines, which specifically state that oxygen accelerates clearance of pneumothorax when drainage is not required 1.

Evidence for Oxygen Therapy in Pneumothorax

The BTS guideline explicitly recommends using a reservoir mask at 15 L/min for patients admitted for observation with pneumothorax, aiming at 100% saturation 1. This recommendation is based on the "nitrogen wash-out theory," which works through the following mechanism:

• High concentration oxygen reduces the partial pressure of nitrogen in the bloodstream
• This creates a greater gradient for nitrogen to move from the pleural space into the bloodstream
• The increased gradient accelerates reabsorption of the pneumothorax

Clinical Evidence

Several studies support this practice:

• Chadha et al. (1983) demonstrated that oxygen therapy increased pneumothorax resolution rates to 4.2% per day compared to 1.25% per day with room air alone - more than tripling the resolution rate 2
• Park et al. (2017) found a significantly higher resolution rate in patients receiving oxygen therapy compared to those breathing room air (4.27% vs. 2.06% per day) 3
• Animal studies consistently show accelerated pneumothorax resolution with supplemental oxygen:
  • Zierold et al. (2000) demonstrated faster resolution with increasing oxygen concentrations in rabbits with visceral pleural injury 4
  • Northfield (1995) showed that rabbits treated with oxygen had resolution by 36 hours, while those on room air required more than 48 hours 5

Clinical Application

When to Use Supplemental Oxygen

• For patients with pneumothorax under observation (not requiring immediate drainage)
• Particularly effective for pneumothoraces smaller than 30% 2
• Use a reservoir mask at 15 L/min, aiming for 100% saturation 1

When Oxygen Therapy Alone Is Insufficient

• Pneumothoraces larger than 30% may not respond adequately to oxygen therapy alone 2
• Patients with hypoxemia or clinical instability require aspiration or drainage in addition to oxygen 1
• Patients with tension pneumothorax require immediate decompression

Important Considerations

• The oxygen therapy should be delivered via a reservoir mask at 15 L/min to maximize the nitrogen gradient 1
• Patients should be monitored for clinical stability, including respiratory rate, heart rate, blood pressure, and oxygen saturation
• Be cautious with high-flow oxygen in patients with COPD due to risk of hypercapnic respiratory failure 6
• Breathless patients should never be left without intervention, regardless of pneumothorax size 6

Follow-up and Monitoring

• Perform serial chest radiographs to monitor resolution
• Continue oxygen therapy until significant resolution is achieved
• Advise patients not to travel by air within 6 weeks of pneumothorax resolution 6

While most of the evidence comes from retrospective studies and animal models, the consistent findings across multiple studies and the explicit recommendation in the BTS guidelines support the use of supplemental oxygen to accelerate pneumothorax resolution when drainage is not required.