Clinical features of medical pneumomediastinum.

Purpose: The clinical features of pneumomediastinum are clarified.

Methods: Eight patients with pneumomediastinum, caused by other than trauma or operative, diagnostic, or therapeutic trouble (medical pneumomediastinum), were studied retrospectively.

Results: There were seven men and one woman with an average age of 17.5 years. The incidence was about 1:320 in thoracic surgical inpatients. The causes were bronchial asthma in three patients, physical exertion in one, and forced swallowing in one. There were three spontaneous cases. The chief complaints were dyspnea in five patients including three patients with bronchial asthma, chest pain in two, and pharyngeal pain in one. Subcutaneous emphysema was observed in all patients. Hamman's sign was audible in only one patient. Roentgenologically, subcutaneous emphysema was observed in all patients. Pneumomediastinum parallel to the heart was observed in five patients. The continuous diaphragm sign was detected in three patients. Five patients were prohibited from eating and drinking excluding those with pneumomediastinum due to bronchial asthma, considering the esophageal origin. Prophylactic antibiotics were prescribed for all patients. Pneumomediastinum improved within 7 days in all patients. The mean length of hospitalization was 7.8 days, ranging from 4 to 13 days.

Conclusion: In consideration of air of the esophageal origin, non per oral was prescribed. With the prevention of mediastinitis using antibiotics, all patients recovered. Emergency endoscopic examination was unnecessary.