Mechanism of injury plays a critical role in the assessment of chest trauma. Understanding how the injury occurred helps providers develop an index of suspicion for injuries that may not be immediately obvious.

Penetrating trauma may result in open chest wounds, pneumothorax, hemothorax, vascular injury, or cardiac injury.

Blunt trauma may result in rib fractures, flail chest, pulmonary contusion, tension pneumothorax, or other internal thoracic injuries.

Understanding mechanism guides assessment priorities and helps providers anticipate injuries before they become apparent. 

A simple principle when evaluating chest trauma:

If it’s open — close it.
If it’s closed — open it.

Open chest injuries require sealing the chest wall defect to prevent further air entry. Closed chest injuries may create pressure within the pleural space that requires decompression to restore ventilation.

Remember: Understanding what caused the injury helps predict what injuries are present.