What type of air accumulation is associated with tension pneumothorax?

Tension pneumothorax occurs when air becomes trapped in the pleural cavity, leading to increased pressure within the thoracic cavity. This pressure can collapse the lung on the affected side and can also shift the mediastinum toward the opposite side, which can compromise cardiac and respiratory function. The accumulation of air in the pleural cavity prevents the lung from expanding fully during inhalation, causing significant respiratory distress and can be life-threatening if not promptly addressed.

Understanding this condition is critical for diving safety, as changes in pressure during a dive can cause barotrauma that may lead to complications such as tension pneumothorax. The emphasis on air in the pleural cavity as the correct choice highlights the specific area where the air accumulation occurs in this medical emergency.