What is the management of secondary spontaneous pneumothorax according to British Thoracic Society (BTS) guidelines?

Management of Secondary Spontaneous Pneumothorax According to BTS Guidelines

According to the British Thoracic Society (BTS) guidelines, secondary spontaneous pneumothorax requires more aggressive management than primary pneumothorax, with specific interventions based on size, symptoms, and patient characteristics. 1

Size Classification and Initial Assessment

• Secondary pneumothorax is classified as "small" or "large" based on the presence of a visible rim of <2 cm or >2 cm between the lung margin and the chest wall on a PA chest radiograph 1
• Clinical symptoms are not reliable indicators of pneumothorax size, with patients having secondary pneumothorax often experiencing breathlessness disproportionate to the size of the pneumothorax 1
• CT scanning is recommended only in specific situations: when differentiating pneumothorax from bullous lung disease, when aberrant tube placement is suspected, or when the plain chest radiograph is obscured by surgical emphysema 1, 2

Management Algorithm Based on Size and Symptoms

For Small Secondary Pneumothorax (<1 cm) with Minimal Symptoms:

• Observation alone is recommended only for small secondary pneumothoraces of less than 1 cm depth or isolated apical pneumothoraces in asymptomatic patients 1
• Hospitalization is required even for these small pneumothoraces 1
• High-flow oxygen (10 L/min) should be administered during observation, with appropriate caution in patients with COPD who may be sensitive to higher oxygen concentrations 1

For All Other Secondary Pneumothoraces:

• Active intervention is required for all other secondary pneumothoraces, regardless of size, if the patient is symptomatic 1
• Simple aspiration is only recommended as initial treatment in small (<2 cm) secondary pneumothoraces in minimally breathless patients under the age of 50 years 1
• Success rates for simple aspiration in secondary pneumothorax are lower (33-67%) compared to primary pneumothorax (59-83%) 1
• Patients with secondary pneumothoraces treated successfully with simple aspiration should be admitted to hospital and observed for at least 24 hours before discharge 1

For Larger Secondary Pneumothoraces or Failed Aspiration:

• Intercostal tube drainage is recommended for larger secondary pneumothoraces (>2 cm) 1
• Intercostal tube drainage is also indicated after failed aspiration 1
• Early discussion with thoracic surgeons is recommended if the lung fails to re-expand or if there is a persistent air leak after 3 days 1

Special Considerations

• Breathless patients should never be left without intervention regardless of the size of the pneumothorax on chest radiograph 1
• The rate of spontaneous resolution/reabsorption of pneumothoraces is approximately 1.25-1.8% of the volume of hemithorax every 24 hours, which can be increased four-fold with high-flow oxygen therapy 1
• Patients with severe bullous lung disease should undergo CT scanning to differentiate emphysematous bullae from pneumothoraces to avoid unnecessary and potentially dangerous aspiration 1

Pitfalls to Avoid

• Do not rely solely on clinical symptoms to determine pneumothorax size, as they are not reliable indicators 1
• Do not discharge patients with secondary pneumothorax treated with simple aspiration without at least 24 hours of observation 1
• Do not delay intervention in breathless patients regardless of pneumothorax size on imaging 1
• Avoid routine use of CT scans in patients with pneumothorax as they add little to the plain PA chest radiograph from the management perspective in most cases 1, 2