Which of the following is a late sign of tension pneumothorax?

• A. Tracheal deviation
• B. Mediastinal shift
• C. Subcutaneous emphysema
• D. JVD

Answer: (B)

In tension pneumothorax, air trapped under pressure in the chest gradually builds up and pushes the mediastinal structures away from the affected side. That progressive displacement of the heart and great vessels is what we call mediastinal shift, and it appears as the condition worsens. Because it represents advanced pressure effects and a move toward cardiovascular compromise, mediastinal shift is considered a late sign of this emergency.

Early signs you might see first include rapid breathing, tachycardia, and signs of impaired venous return such as neck vein distention. Subcutaneous emphysema can occur with chest injuries but isn’t a reliable indicator of a tension state, and tracheal deviation can accompany mediastinal shift but is not the defining late feature in this context. In any suspected tension pneumothorax, prompt decompression is critical.