What is the definition of an open pneumothorax?

An open pneumothorax is defined as an open wound that permits air to enter the pleural space, leading to lung collapse. This condition occurs when there is a breach in the chest wall—such as a stab wound or gunshot wound—that allows external air to flow directly into the pleural cavity. When this happens, the pressure dynamics in the pleural space are disrupted, preventing the lung on the affected side from fully expanding. The resulting breathing difficulties and reduced oxygenation can quickly become life-threatening.

Understanding this definition is crucial for emergency medical responders, as rapid assessment and intervention are necessary to manage the airway and prevent further complications. Other options describe alternative scenarios that do not accurately capture the specifics of an open pneumothorax, such as closed wounds or infections, which involve different pathophysiological processes and treatment approaches.