Which chest trauma produces a paradoxical chest wall movement due to multiple rib fractures?

• A. Sucking chest wound
• B. Flail segment
• C. Cardiac contusion
• D. Heat cramps

Answer: (B)

Paradoxical chest wall movement signals an unstable chest wall caused by a flail segment. When multiple adjacent ribs are fractured in multiple places, the broken portion becomes detached from the rest of the chest. During breathing, this segment moves opposite to the rest of the chest: it sinks inward during inspiration as negative intrathoracic pressure pulls it in, and bulges outward during expiration as positive pressure pushes it out. This instability impairs ventilation and can lead to respiratory distress, making prompt airway support, pain control, and chest stabilization essential.

The conditions listed do not produce this paradoxical motion. An open chest wound (sucking chest wound) involves air entering through a chest wall defect, not an inverted segment during breathing. Cardiac contusion affects the heart and may cause chest pain or rhythm disturbances rather than abnormal chest wall movement. Heat cramps are unrelated to chest trauma.