What is a common sign of tension pneumothorax?

A common sign of tension pneumothorax is the presence of absent breath sounds on one side of the chest. In this condition, air enters the pleural space and cannot escape, resulting in increasing pressure that collapses the lung on the affected side. This pressure differential can lead to the trachea deviating away from the affected side and a significant reduction in breath sounds, as the lung cannot expand normally to facilitate airflow.

When evaluating the other options, decreased respiratory rate is often not typically associated with tension pneumothorax, as patients may exhibit rapid breathing due to respiratory distress. Heart rate stabilization would not occur in a tension pneumothorax; instead, the heart rate often increases as the body responds to the hypoxia and cardiopulmonary compromise. Increased mobility does not fit the clinical picture, since patients with tension pneumothorax tend to be in significant distress and may exhibit reduced mobility due to pain or respiratory difficulty. Hence, absent breath sounds on one side serves as a key indicator of this critical condition.