Spontaneous pneumomediastinum: 41 cases.

Objective: Spontaneous pneumomediastinum is characterized by the presence of interstitial air in the mediastinum without any apparent precipitating factor. The purpose of this study is to review and discuss our experience with this condition.

Methods: A descriptive, retrospective study of 41 cases--34 men (83%) and 7 women (17%)--treated at our hospital for spontaneous pneumomediastinum from January 1990 through June 2006.

Results: The mean age of the patients was 21 years (range, 14-35 years). Notably, 22% of patients had a prior history of asthma. No precipitating factor was identified in 51% of cases while onset was associated with physical effort in 12%. Chest pain (85%) and dyspnea (49%) were the most common symptoms. Subcutaneous emphysema, which presented in 71% of patients, was the most common sign. Pneumomediastinum was diagnosed by plain chest radiography in all cases. In certain cases, a computed tomography scan of the chest, contrast-enhanced swallow, or bronchoscopy was performed. All patients were admitted to the hospital with good progress and no instances of morbidity or mortality. Treatment included analgesia, rest, and/or initial oxygen therapy. The mean length of hospital stay was 5 days (range, 1-9 days) with only one case of early recurrence, which was resolved satisfactorily.

Conclusions: Spontaneous pneumomediastinum is a benign process primarily affecting young men. Despite its low incidence, spontaneous pneumomediastinum should be considered in the differential diagnosis of acute chest pain because it requires a high index of suspicion. Patients with spontaneous pneumomediastinum respond well to medical treatment, with no recurrence in the great majority of cases.