Spontaneous pneumomediastinum (SP) is defined as the presence of mediastinal free air in the absence of an obvious precipitating cause and should not be confused with pneumomediastinum occurring in the setting of gross trauma or positive-pressure mechanical ventilation in intubated patients, or catastrophic events such as blunt or penetrating trauma, infection due to gas producing organisms, retropharyngeal perforation or esophageal rupture1,2.
SP frequently occurs in young men (Figure) and is associated with a variety of factors, most commonly illicit inhalational drug use (eg, marijuana, cocaine) and performance of a Valsalva-type maneuver causing alveolar rupture2. Ecstasy (3,4-methylenedioxymethamphetamine –MDMA) ingestion is also associated with SP, possibly related to its attendant physical hyperactivity (eg dancing, sexual activity) or a contaminant that may predispose to alveolar rupture3,4. Other causes not related to illicit drug use include childbirth, forceful straining during exercise, straining at stool, coughing, sneezing, retching/vomiting, pulmonary function testing, and inflation of party balloons1!
SP should always be distinguished from complicated pneumomediastinum (eg, in the setting of perforated viscus, trauma, gas-forming organisms), as it usually follows a very benign course with patients recovering without specific intervention1,2,5.
Figure: Spontaneous pneumomediastinum due to vigorous exercise in a young male
- Newcomb AE, Clarke CP. Spontaneous pneumomediastinum: A benign curiosity or a significant problem? CHEST 2005;128:3298-3302. https://www.ncbi.nlm.nih.gov/pubmed/16304275
- Panacek EA, Singer AJ, Sherman BW, et al. Spontaneous pneumomediastinum: clinical and natural history. Ann Emerg Med 1992;21:1222-27. https://www.ncbi.nlm.nih.gov/pubmed/1416301
- Gungadeen A, Moor J. Extensive subcutaneous emphysema and pneumomediastinum after ecstasy ingestion. Case Rep Otolaryngol 2013; http://dx.doi.org/10.1155/2013/79587
- Stull BW. Spontaneous pneumomediastinum following ecstasy ingestion and sexual intercourse. Emerg Med J 2008;25:113-14. https://www.ncbi.nlm.nih.gov/pubmed/18212154
- Kelly S, Hughes S, Nixon S, et al. Spontaneous pneumomediastinum (Hamman’s syndrome). Surgeon 2010;8:63-66. https://www.ncbi.nlm.nih.gov/labs/articles/20303884