SPONTANEOUS MEDIASTINAL EMPHYSEMA

Mediastinal emphysema following stab wounds or other trauma of the chest has long been recognized. It has also been described as occurring secondary to violent coughing, bronchial asthma, artificial pneumothorax, pneumonia, difficult labor, straining at stool and other forms of extreme effort. McGuire and Bean¹ point out that Laennec² described grating sounds and bubbling rales during respiration as diagnostic of subpleural and interlobar emphysema. Skoda³ subsequently confirmed these signs, and von Rokitansky⁴ described the pathologic aspects of the condition. Müller⁵ noted the presence of bubbling crepitations that occurred with the heart beat and the occasional disappearance of cardiac dulness. He observed that the presence of subcutaneous emphysema aided in making the diagnosis of mediastinal emphysema.

Rees and Hughes⁶ in a report on wounds of the chest encountered during World War I noted loud "tapping" sounds over the cardiac area in 9 cases of wounds of the left