Tension Pneumothorax: NEET PG Radiology
NEET PG Note: Tension Pneumothorax is a clinical diagnosis. NEVER request a chest X-ray if you suspect it!
1. Classic Radiographic “Tension” Signs
If an X-ray is obtained (e.g., as an incidental finding in a stable patient), these are the high-yield indicators of high intrathoracic pressure:
- Contralateral Mediastinal Shift: The heart and trachea are pushed away from the affected side.
- Diaphragmatic Inversion: The hemidiaphragm on the affected side is flattened or pushed inferiorly (convexity reversed).
- Increased Intercostal Space Widening: Due to lung expansion against the thoracic wall.
- Complete Lung Collapse: Often appearing as a small, dense “stump” at the hilum.
2. High-Yield Comparison Table
| Feature | Tension vs. Simple Pneumothorax |
|---|---|
| Mediastinum | Shifted to the contralateral side in tension. |
| Diaphragm | Flattened or inverted in tension. |
| Hemodynamics | Shock (hypotension/tachycardia) is the hallmark of tension. |
3. Key NEET PG Concepts
- The “Lung Point”: On Ultrasound, the presence of a “lung point” (the transition between moving lung and stationary pleural space) is highly specific for pneumothorax. It is absent in a tension pneumothorax because the lung is completely collapsed away from the chest wall.
- Deep Sulcus Sign (Supine X-ray): A radiolucent (dark) and deep costophrenic angle on a supine film is the most sensitive sign for a pneumothorax in trauma patients.
- Treatment Update: Remember the shift in ATLS guidelines: Needle decompression is now preferred in the 5th intercostal space, anterior axillary line (the “safe triangle” zone), which is safer than the traditional 2nd intercostal space.