A respiratory abnormality that is characterized by inflammation of the mediastinum (the chest cavity, which contains the heart, the thymus gland, some lymph nodes, and parts of the esophagus, aorta, thyroid, and parathyroid glands) as the result of bleeding. [ url:https://www.merckmanuals.com/home/lung-and-airway-disorders/pleural-and-mediastinal-disorders/mediastinitis ]