Advanced Patient Assessment Practice Exam 2026 – Comprehensive Prep Resource

The expiratory view is particularly beneficial in identifying a pneumothorax because it emphasizes the presence of air in the pleural space. During expiration, the lung volume decreases, allowing any air that has entered the pleural cavity to become more apparent on imaging. In a normal situation, the lung may appear more collapsed, making it easier to see the visceral pleura and any air between the lung and chest wall. This contrast allows clinicians to differentiate between a normal and an abnormal pleural space.

In contrast, while other views such as the lateral decubitus or AP view can provide useful information, they are not as specifically focused on demonstrating a pneumothorax. The lateral decubitus view can occasionally reveal free air but is less definitive than the expiratory view. The left lateral view and AP view generally do not enhance the visibility of a pneumothorax in the same way, especially because they do not optimally highlight the air-fluid interfaces that become critical in the diagnosis of a pneumothorax.