Which injury is described as a lung bruise that worsens over time?

• A. Pulmonary Contusion
• B. Pneumothorax
• C. Flail Chest
• D. Open Pneumothorax

Answer: (A)

Pulmonary contusion is bruising of the lung tissue caused by blunt chest trauma, with bleeding and edema developing within the parenchyma. This injury often looks mild at first but can worsen over the next hours as hemorrhage and inflammatory edema expand, leading to impaired gas exchange. That delayed, progressive deterioration is what makes it the best fit for a “lung bruise that worsens over time.” Clinically, patients may become more hypoxic despite initially okay findings, and imaging can evolve from subtle or normal early on to patchy, ill-defined opacities in the affected area on later studies.

Pneumothorax involves air in the pleural space causing lung collapse, not a bruise of the lung tissue. Flail chest refers to a segment of chest wall instability from multiple rib fractures, not lung contusion. Open pneumothorax is a penetrating chest wound with air entering the chest cavity, again not a parenchymal bruise.