Which physical sign is indicative of a tension pneumothorax?

A tension pneumothorax occurs when air becomes trapped in the pleural space and exerts pressure on the lungs and mediastinum, pushing structures such as the trachea and heart away from the affected side. Therefore, tracheal deviation away from the side of the tension pneumothorax is a key physical sign. This occurs because the increased pressure on one side forces the mediastinal structures to shift towards the unaffected side, making it observable that the trachea is displaced away from the side with the tension.

In cases of symmetrical chest rise, the presence of balanced lung expansion indicates no significant pneumothorax or tension build-up, which contradicts the scenario being assessed. Similarly, a decreased respiratory rate might suggest a different issue, such as respiratory distress or failure, but is not a direct indicator of a tension pneumothorax. Lastly, if the trachea deviates towards the affected side, it would imply a shift towards where the pressure is not present, which is not consistent with the pathophysiology of a tension pneumothorax.