Mediastinal and Subcutaneous Emphysema Following Pulmonary Function Tests1, 2

Mediastinal and subcutaneous emphysema occurred in a healthy 23-year-old medical student after routine spirometric studies. This complication has not previously been reported. It is postulated that the maximal inspiratory effort before the forced expiration resulted in rupture of paraseptal blebs along the bronchovascular septa with dissection of air to the lung hilus and mediastinum, up the carotid sheaths to the neck, and thence to subcutaneous tissue planes.