Management of Secondary Spontaneous Pneumothorax

Introduction to Guidelines

The British Thoracic Society recommends that secondary spontaneous pneumothorax requires more aggressive management than primary pneumothorax, with specific interventions based on size, symptoms, and patient characteristics 1, 2

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 2, 3
Clinical symptoms are not reliable indicators of pneumothorax size, with patients having secondary pneumothorax often experiencing breathlessness disproportionate to the size of the pneumothorax 4

The British Thoracic Society guidelines recommend observation alone only for small secondary pneumothoraces of less than 1 cm depth or isolated apical pneumothoraces in asymptomatic patients 1, 2
Hospitalization is required even for these small pneumothoraces 1, 5
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, 2
Active intervention is required for all other secondary pneumothoraces, regardless of size, if the patient is symptomatic 1, 5
Simple aspiration is only recommended as initial treatment in small (<2 cm) secondary pneumothoraces in minimally breathless patients under the age of 50 years 5, 6
Success rates for simple aspiration in secondary pneumothorax are lower (33-67%) compared to primary pneumothorax (59-83%) 6
Patients with secondary pneumothoraces treated successfully with simple aspiration should be admitted to hospital and observed for at least 24 hours before discharge 5, 6
Intercostal tube drainage is recommended for larger secondary pneumothoraces (>2 cm) 1, 2
Intercostal tube drainage is also indicated after failed aspiration 5, 6

Breathless patients should never be left without intervention regardless of the size of the pneumothorax on chest radiograph 1, 2
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, 5
Patients with severe bullous lung disease should undergo CT scanning to differentiate emphysematous bullae from pneumothoraces to avoid unnecessary and potentially dangerous aspiration 2, 4

Do not rely solely on clinical symptoms to determine pneumothorax size, as they are not reliable indicators 4
Do not discharge patients with secondary pneumothorax treated with simple aspiration without at least 24 hours of observation 5, 6
Do not delay intervention in breathless patients regardless of pneumothorax size on imaging 1, 2
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 3

In patients with severe bullous lung disease, obtain an immediate CT scan to definitively differentiate emphysematous bullae from a true pneumothorax. 7
Plain chest radiographs routinely underestimate pneumothorax volume and cannot reliably distinguish bullae from pneumothorax in complex cystic lung disease. 7

Measure the visible rim between the lung margin and the chest wall on a postero‑anterior (PA) radiograph; this measurement is used to classify pneumothorax size. 7
Define a small pneumothorax as a rim < 2 cm and a large pneumothorax as a rim > 2 cm. 7

For any symptomatic pneumothorax—regardless of radiographic size—insert an intercostal chest tube immediately; observation alone is inappropriate. 7
Use a 16‑F to 22‑F chest tube in most patients. 8
Connect the tube to a water‑seal device initially; apply suction only if the lung fails to re‑expand. 8
Marked breathlessness even with a small (< 2 cm) pneumothorax may herald tension physiology and warrants urgent tube placement. 7

Deliver high‑flow oxygen (≈ 10 L/min) to accelerate pneumothorax reabsorption roughly four‑fold, increasing the reabsorption rate from ~1.5 % to ~7 % of the hemithorax volume per 24 h. 7
In patients with chronic obstructive pulmonary disease, monitor oxygen saturation closely because high‑flow oxygen can precipitate CO₂ retention. 7

Only in truly asymptomatic patients with a very small (< 1 cm) or isolated apical pneumothorax may hospitalization with observation be considered without immediate tube drainage. 7

Remove the chest tube in a staged manner after complete radiographic resolution and no clinical evidence of air leak. 8
First discontinue suction, then observe the patient with the tube still in place. 8
Obtain a repeat chest radiograph 5–12 hours after the last documented air‑leak before final tube removal. 8

Do not rely on clinical symptoms alone to gauge pneumothorax size in bullous emphysema; breathlessness is often disproportionate to radiographic findings. 7
Do not delay any intervention in a breathless patient, even if the pneumothorax appears small on imaging. 7
Do not attempt routine aspiration of a suspected pneumothorax in bullous emphysema without prior CT confirmation, to avoid inadvertently puncturing a bulla. 7
Reserve pre‑operative CT for complex cases where bullae cannot be distinguished from pneumothorax; it is not required for routine simple pneumothorax management decisions. 7