Relationship between initial post-aspiration chest radiograph (CXR) and tracer gas status and the outcome of secondary spontaneous pneumothorax
| n | No further intervention | Intercostal drain | Re-aspiration | |
| CXR improved; tracer gas –ve | 6 | 6 (100%) | 0 | 0 |
| CXR improved; tracer gas +ve | 20 | 8 (40%) | 11 (55%) | 1 (5%) |
| CXR not improved; tracer gas –ve | 1 | 0 | 1 (100%) | 0 |
| CXR not improved; tracer gas +ve | 4 | 0 | 3 (75%) | 1 (25%) |
| CXR not performed; tracer gas +ve | 4 | 0 | 4 (100%) | 0 |
CXR improved = significant reduction in size of the pneumothorax; CXR not improved = pneumothorax unchanged in size or larger.