Mediastinal emphysema complicating trachetotomy.

The fact that mediastinal emphysema has only latterly been given serious attention as a complication of tracheotomy does not imply that it is rare but that its diagnosis presents difficulty (Michels, 1939). This author pointed out, as did Neffson (1943), Macklin and Macklin (1944), Stothers (1956), and Nicholas (1958), that mediastinal emphysema is far commoner than is suggested by the literature. Stothers and Nicholas have both studied the pathogenesis and clinical features of the disorder and given detailed reviews of the earlier literature in the sphere. It now seems practically certain that the chief cause of this complication is the increase in negative intrathoracic pressure brought about by respiratory obstruction which results in the intake of air at the tracheotomy procedure itself. The most critical step in the operation is the incision of the pretracheal fascia, since air appears most readily to be drawn in between this fascial plane and