What is pneumothorax in the context of mechanical ventilation?

• A. Fluid in the pleural cavity
• B. Air in the pleural cavity
• C. Blood in the pleural cavity
• D. Presence of pneumonia.

Answer: (B)

Pneumothorax refers specifically to the presence of air in the pleural cavity, which is the space between the lung and the chest wall. In the context of mechanical ventilation, this condition is particularly significant because it can lead to lung collapse (atelectasis) and significantly impair respiratory function. When a patient is on mechanical ventilation, changes in intra-thoracic pressure can facilitate the entry of air into this space, especially if there is a rupture in the lung tissue or pleura. This can complicate mechanical ventilation settings and may require immediate intervention to re-establish normal pressures and facilitate lung re-expansion. Understanding pneumothorax in this way is crucial for healthcare providers managing ventilated patients, as it is a potential complication that may arise during respiratory support.