pulmonary disorders
Pneumomediastinum
Introduction
Pneumomediastinum is air in mediastinal interstices. Themain causesof pneumomediastinum are Alveolar rupture with dissection of air into the interstitium of the lung with translocation to the mediastinum Esophageal perforation Acute Perforation of the Gastrointestinal Tract with dissection of air from the neck or the abdomen into the mediastinum Tension pneumomediastinum with compression of mediastinal structures is rare. The primary symptom is substernal chest pain which can, on occasion, be severe. Physical examination may show subcutaneous emphysema, usually in the suprasternal notch, along with a crunching or clicking noise synchronous with the heartbeat; this noise is best heard over the heart when the patient is in the left lateral decubitus position (Hamman sign). The diagnosis is confirmed by chest x-ray, which shows air in the mediastinum. The cause of pneumomediastinum must be identified to rule out esophageal perforation, which requires hospitalization and treatment. Although pneumomediastinum may produce dramatic findings on examination and/or x-ray and may indicate a serious disorder, treatment of pneumomediastinum itself is usually unnecessary. 