Traumatic asphyxia mechanism?

• A. Hypovolemia due to bleeding
• B. Airway obstruction due to edema
• C. Intense compression of the thoracic cavity causing venous back flow to the right side of the heart
• D. Pulmonary edema

Answer: (C)

Traumatic asphyxia results from a sudden, intense compression of the chest that sharply raises intrathoracic pressure. That pressure exceeds the venous pressure returning to the heart, so venous blood can't get back to the right side of the heart and instead backs up into the veins of the head and neck. The elevated venous pressure causes capillary rupture in facial and cervical tissues, leading to facial plethora, edema, and petechial hemorrhages, particularly in the eyes. When the compression is released, the sudden return of blood can cause symptoms, but the hallmark mechanism is the forced thoracic compression creating venous back flow toward the right side of the heart. This differs from hypovolemia from bleeding, airway obstruction from edema, or pulmonary edema, which arise from different processes.