Treatment for Small Pneumothorax
The treatment of a small pneumothorax fundamentally depends on whether it is primary (no underlying lung disease) or secondary (underlying lung disease present), with primary pneumothorax managed by observation alone if minimally symptomatic, while secondary pneumothorax requires active intervention except in extremely limited circumstances. 1
Primary Pneumothorax Management
Observation Strategy
- For small primary pneumothorax (<2 cm rim between lung margin and chest wall) without significant breathlessness, observation is the treatment of choice. 2, 1
- These patients can be discharged with outpatient follow-up rather than hospitalized, as 70-80% resolve spontaneously without intervention. 2, 1
- Patients must receive clear written instructions to return immediately if breathlessness develops. 1
When Intervention Is Required
- If the patient has any breathlessness, intervention is mandatory regardless of radiographic size. 2, 1
- Simple aspiration should be attempted first for symptomatic primary pneumothorax, with success rates of 59-83%. 1
- Use a small-bore catheter for aspiration; if the first attempt fails and <2.5 liters were aspirated, re-aspiration can be attempted. 1
- If aspiration fails, proceed to small-bore chest tube (10-14F) attached to a Heimlich valve or water seal device. 1
Secondary Pneumothorax Management
Critical Distinction
- Observation alone is only acceptable for secondary pneumothorax if the pneumothorax is <1 cm depth or isolated apical AND the patient is completely asymptomatic. 1, 3
- All other small secondary pneumothoraces require active intervention due to poor respiratory reserve from underlying lung disease. 1, 3
- Even observed cases require hospitalization. 3
Active Intervention Approach
- Chest tube drainage is the primary treatment for most secondary pneumothoraces, as simple aspiration has much lower success rates (33-67%) compared to primary pneumothorax. 1, 3
- Simple aspiration may only be attempted in highly selected patients: age <50 years, minimally breathless, pneumothorax <2 cm. 3
- Age >50 years reduces aspiration success to only 19-31%, making chest tube insertion the clear choice in older patients. 3
Essential Adjunctive Therapy
High-Flow Oxygen
- Administer high-flow oxygen (10 L/min) to all hospitalized patients, as this increases pneumothorax reabsorption rate four-fold. 2, 1, 3
- Without oxygen, natural reabsorption is only 1.25-1.8% of hemithorax volume per 24 hours, meaning a 15% pneumothorax takes 8-12 days to resolve. 1, 3
- With supplemental oxygen, this reduces to 2-3 days. 4
- Use caution in COPD patients who may be CO2 retainers. 2, 1, 3
Size Classification
Measurement Standards
- Small pneumothorax is defined as <2 cm rim between lung margin and chest wall on chest radiograph. 2, 1, 3
- Large pneumothorax is ≥2 cm rim (or ≥3 cm apex-to-cupola distance by some criteria). 3
- Plain radiographs typically underestimate pneumothorax size; CT scanning is most accurate when exact measurement is needed. 2
Common Pitfalls to Avoid
Clinical Judgment Over Imaging
- Never rely solely on pneumothorax size to guide treatment—clinical symptoms trump radiographic size. 1
- Any breathless patient requires immediate intervention regardless of measured size. 2, 3
Secondary Pneumothorax Errors
- Do not attempt observation for secondary pneumothorax unless it meets strict criteria (<1 cm depth, isolated apical, completely asymptomatic). 1, 3
- Do not discharge patients with secondary pneumothorax after successful aspiration without 24-hour hospitalization. 1
- Do not apply suction immediately after chest tube insertion; wait 48 hours for persistent air leak before adding suction. 1