If air collects in the pleural space and cannot escape, what is this condition called?

• A. Open pneumothorax
• B. Tension pneumothorax
• C. Pleural effusion
• D. Hemothorax

Answer: (B)

Air trapped in the pleural space that cannot escape creates a one-way valve effect, causing a progressive rise in intrapleural pressure. This pushes the lung on the affected side toward collapse and shifts the mediastinum, which can compress the heart and great vessels and rapidly reduce venous return. That dangerous combination is the hallmark of a tension pneumothorax.

This differs from an open pneumothorax, where air can move in and out through a chest wall defect and pressure buildup is not as extreme. Pleural effusion is fluid in the pleural space, not air. Hemothorax is blood in the pleural space. In tension pneumothorax, the trapped air creates acute respiratory and cardiovascular compromise, making it a medical emergency requiring immediate decompression followed by chest tube placement.