Flail chest is a chest wall injury of 3 or more adjacent ribs with fractures that cause that section of rib cage to separate from the chest wall and move independently of the rest of the rib cage. Flail chest is usually caused by blunt trauma but may occur during thoracic surgery. It is considered a medical emergency.

Flail chest is characterized by pleuritic chest pain, ecchymosis, and dyspnea. A more difficult to detect symptom is abnormal chest motion.

Commonly associated injuries include pneumothorax, hemothorax, and pulmonary contusion. Intraabdominal, upper extremity, and head injuries are also often seen due to the severe mechanism of injury needed to cause flail chest.

Management begins with oxygen administration, monitoring for signs of respiratory failure, noninvasive positive airway pressure administration by mask, and analgesia. More severe conditions may require endotracheal intubation and mechanical ventilation.