What is an open pneumothorax?

An open pneumothorax occurs when the parietal pleura, which lines the chest wall, is punctured, allowing outside air to enter the pleural cavity. This condition can happen due to a traumatic injury such as a stab or gunshot wound, creating a direct channel for air to flow from the atmosphere into the pleural space. As air enters the pleural cavity, it disrupts the negative pressure that normally keeps the lung expanded, potentially leading to lung collapse on the affected side.

In an open pneumothorax, the imbalance created by the influx of air can compromise respiratory function and can be life-threatening if not treated promptly. The condition is characterized by the inability of the lung to fully expand due to this introduction of external air, leading to difficulty in breathing and reduced oxygenation of the blood.