Clinical aspects of mediastinal emphysema (pneumomediastinum)

The etiology of spontaneous mediastinal emphysema is varied. Two illustrative cases are described, one related to bronchial asthma, and the other to scuba diving. The characteristic clinical findings, including subcutaneous emphysema and the abnormal auscultatory signs are discussed. These two cases illustrate two widely different etiologies of the syndrome. In both cases three classical signs associated with pneumomediastinum were elicited. A review of the literature of the subject discussed is also provided. Furthermore, the differential diagnosis, including the close resemblance of mediastinal emphysema to a left medial pneumothorax is considered. The diagnostic importance of a left lateral chest X-ray taken in expiration is stressed. Management should be conservative unless clinical deterioration continues.peer-reviewe