What is characterized by abnormal chest movement during breathing?

Paradoxical movement refers to an abnormality in chest wall movement that occurs during breathing, specifically when one part of the chest moves in the opposite direction of the rest of the chest during inhalation and exhalation. This often results from conditions such as a rib fracture or flail chest, where multiple ribs are broken, leading to a segment of the chest wall moving inwards when the patient tries to inhale and outwards when exhaling. This improper movement not only hampers effective ventilation but may also indicate significant underlying injury to the thoracic cavity.

In contrast, raccoon eyes are indicative of basilar skull fractures and don't relate to abnormal respiratory patterns. Pneumothorax describes the presence of air in the pleural space, which can lead to diminished breath sounds but does not typically affect the mechanical movement of the chest wall in the paradoxical manner described. Pulmonary embolism involves a blockage in the pulmonary arteries and may affect oxygenation and breathing but is not characterized by abnormal chest wall movement as noted in paradoxical movement. Understanding these distinctions highlights why paradoxical movement is the correct answer when identifying abnormal chest movement during breathing.