Which sign is a late, life-threatening sign of a tension pneumothorax?

• A. Tachycardia
• B. Jaundice
• C. Cyanosis
• D. Hypotension with tracheal deviation

Answer: (D)

In tension pneumothorax, air under pressure builds in the pleural space and shifts the mediastinum, which severely impairs venous return to the heart and drops cardiac output. Early signs are about respiratory distress and compensatory heart rate increases. The truly dangerous, late sign is the combination of hypotension and tracheal deviation away from the affected side, reflecting the severe compression of great vessels and the heart. This is the emergency cue that decompression is urgently needed. Cyanosis can occur with profound hypoxemia but is not the defining late sign, and tachycardia or jaundice don’t capture the life-threatening mediastinal shift and hemodynamic collapse.