What is the treatment for a small pneumothorax?

Treatment of Small Pneumothorax

For small pneumothoraces, observation alone is recommended for asymptomatic or minimally symptomatic patients, with high-flow oxygen therapy (10 L/min) to accelerate reabsorption when hospitalized. 1, 2

Definition of Small Pneumothorax

• A small pneumothorax is defined as having a visible rim of <2 cm between the lung margin and chest wall on chest radiograph 1
• Plain PA radiographs typically underestimate pneumothorax size; CT scanning is more accurate but only recommended for difficult cases 1

Treatment Algorithm Based on Pneumothorax Type and Symptoms

Primary Pneumothorax (no underlying lung disease)

• Small with minimal symptoms:

  • Observation alone is sufficient 1, 2
  • No hospital admission required 1
  • Patient should be instructed to return if breathlessness develops 1
  • 70-80% of pneumothoraces smaller than 15% have no persistent air leak 1
  • Recurrence rates are lower with observation compared to intercostal tube drainage 1

• Small but symptomatic:

  • Simple aspiration as first-line treatment 1, 2
  • If aspiration fails, proceed to intercostal tube drainage 2
  • Marked breathlessness with a small pneumothorax may indicate tension pneumothorax requiring immediate intervention 1

Secondary Pneumothorax (with underlying lung disease)

• Small (<1 cm depth) and asymptomatic:

  • Observation alone is recommended 1, 3
  • Hospital admission is required for monitoring 1
  • High-flow oxygen (10 L/min) should be administered with caution in COPD patients 1

• Small but symptomatic or >1 cm:

  • Active intervention required 1
  • Simple aspiration may be attempted in minimally breathless patients under 50 years 1
  • If aspiration is successful, patient should be observed for at least 24 hours before discharge 1
  • Intercostal tube drainage if aspiration fails 2

Oxygen Therapy

• High-flow oxygen (10 L/min) accelerates pneumothorax reabsorption by up to four times 1, 2
• Oxygen reduces nitrogen partial pressure in pleural capillaries, increasing the pressure gradient for air absorption 1
• A 15% pneumothorax takes approximately 8-12 days to resolve naturally but much faster with oxygen therapy 1
• Use with caution in patients with COPD who may be sensitive to higher oxygen concentrations 1

Follow-up Care

• Natural reabsorption rate of pneumothoraces is 1.25-1.8% of hemithorax volume every 24 hours 1
• Patients discharged after observation should receive clear instructions to return if breathlessness worsens 1
• Avoid air travel until complete resolution is confirmed on follow-up chest radiograph 2

Pitfalls and Caveats

• Never leave breathless patients without intervention regardless of pneumothorax size on chest radiograph 1
• Most patients with primary pneumothoraces who fail observation treatment and require drainage actually have secondary pneumothoraces 1
• Observation strategy for traumatic pneumothoraces may result in shorter hospital stays (3.6 vs 5.8 days) compared to immediate tube thoracostomy 4
• Manual aspiration has a 90% success rate for moderate pneumothoraces, reducing the need for catheter insertion 5