What do pulmonary function tests (PFTs) typically show in patients with chest trauma?

Pulmonary function tests (PFTs) are critical for assessing lung function, and in patients with chest trauma, they typically reveal decreased lung volumes and capacities. This is primarily due to the effects of injury, such as pneumothorax, hemothorax, or rib fractures, which can restrict lung expansion, impede airflow, and compromise effective ventilation.

The presence of pain from rib injuries can also lead to shallow breathing and inadequate lung inflation, further reducing lung volumes and capacities. Additionally, if there is any disruption to the pleural space, such as occurs in pneumothorax, it can result in a significant decrease in lung compliance, leading to a reduction in the volume of air the lungs can hold.

Thus, the key takeaway is that chest trauma leads to functional impairment and decreased respiratory mechanics, which is reflected in PFT results showing lower volumes and capacities.