Which condition in the pleural space can occur after trauma and presents with blood accumulation?

• A. Chylothorax
• B. Pleural effusion
• C. Hemothorax
• D. Pneumothorax

Answer: (C)

Blood in the pleural space after trauma is a hemothorax. When chest injury tears vessels in the chest wall or lung, blood leaks into the pleural cavity and accumulates, compressing the lung and impairing ventilation. Clinically this shows up as sudden shortness of breath with dullness to percussion and reduced breath sounds on the affected side; large volumes can lead to hypovolemia and shock. This differs from chylothorax, which involves chyle (milky fluid from thoracic duct injury) and from a generic pleural effusion, which is fluid buildup that isn’t necessarily blood. Pneumothorax involves air in the pleural space and presents with hyperresonance and decreased breath sounds, not blood.