Paradoxical chest motion is best described as:

• A. It is when the chest wall expands uniformly with inhalation
• B. It only occurs in pediatric patients
• C. It improves spontaneously with rest
• D. It occurs when part of the chest moves inward on inspiration while another part moves outward on expiration

Answer: (D)

Paradoxical chest motion occurs when a segment of the chest wall moves in the opposite direction to the rest of the chest during breathing. In a normal breath, the chest expands on inspiration and recoils on expiration. If a portion of the chest wall is fractured and detached (a flail segment), that part can be drawn inward during inspiration as the surrounding chest expands, and it can bulge outward during expiration as the rest of the chest recoils. This opposite movement is why the description fits best: part moves inward on inspiration while another part moves outward on expiration.

This sign points to significant blunt chest trauma and potential respiratory compromise, so focus on securing the airway and breathing, delivering high-flow oxygen, and preparing for rapid transport. Analgesia and ventilation support may be necessary to stabilize the chest wall and improve oxygenation.