What condition occurs when air escapes from an injured lung and pressure builds up in the chest?

The condition that occurs when air escapes from an injured lung and pressure builds up in the chest is known as tension pneumothorax. This situation arises when air enters the pleural space and cannot escape, leading to increased pressure within the thoracic cavity. The increasing pressure can compress the lungs and other vital structures, causing respiratory distress and impaired circulation.

In tension pneumothorax, the one-way valve effect allows air to enter the pleural space during inhalation, but prevents its escape during exhalation. This can result in a mediastinal shift, compromising cardiovascular and respiratory function, which makes it a critical emergency requiring immediate intervention.

Understanding the mechanics of how air enters and affects the thoracic cavity is crucial for medical professionals in emergency situations to ensure appropriate and timely treatment is administered.