Spontaneous pneumomediastinum: clinical and natural history

Ann Emerg Med. 1992 Oct;21(10):1222-7. doi: 10.1016/s0196-0644(05)81750-0.


Study objective: To evaluate the clinical characteristics and natural history of patients presenting with spontaneous pneumomediastinum.

Design: A retrospective case series was conducted to identify patients diagnosed with spontaneous pneumomediastinum. ICD-9 discharge codes were used for 1984 to 1990 at two institutions, and emergency department records of a third hospital were reviewed for 1981 to 1986. Clinical features, interventions, complications, setting, etiology, symptoms, and length of hospital stay were recorded.

Setting: Three university tertiary care hospitals.

Participants: All ED patients more than 12 years old with a diagnosis of spontaneous pneumomediastinum.

Interventions: None.

Results: Seventeen cases were identified. Age range was 15 to 41 years (mean, 25 years). Presenting symptoms were chest pain in eight (47%), dyspnea in three (18%), both symptoms in three (18%), and neither in three (18%). Three patients complained only of throat discomfort. Nine (52%) had a Hamman's crunch, 11 (65%) had subcutaneous emphysema, and two (11%) had a small pneumothorax. Five (29%) were smokers, and five (29%) had normal esophograms. Thirteen of 17 (76%) cases were associated with illicit inhalation drug use. Twelve cases (70%) had history of a "Valsalva-type" maneuver. All but three were admitted to a hospital, with a mean stay of 2.5 days (range, one to six). No patient suffered complications or required interventions for spontaneous pneumomediastinum. Specifically, no patient developed a subsequent pneumothorax or airway compromise. The three patients not admitted were followed up by telephone contact. All did well with rapid resolution of their symptoms.

Conclusion: Most spontaneous pneumomediastinum cases occur in the setting of inhalational drug use. One hundred percent of patients will have a symptom directly related to the spontaneous pneumomediastinum, with 82% presenting with either dyspnea or chest pain. Most (88%) will present with either subcutaneous emphysema or a Hamman's crunch on examination. Simple spontaneous pneumomediastinum has a very benign course and does not require hospitalization. Serial radiographs, likewise, did not change the medical management of spontaneous pneumomediastinum.

MeSH terms

  • Administration, Inhalation
  • Adolescent
  • Adult
  • Auscultation
  • Chest Pain / etiology
  • Dyspnea / etiology
  • Electrocardiography
  • Female
  • Humans
  • Illicit Drugs / adverse effects*
  • Male
  • Mediastinal Emphysema / complications
  • Mediastinal Emphysema / diagnosis
  • Mediastinal Emphysema / etiology*
  • Retrospective Studies
  • Subcutaneous Emphysema / complications


  • Illicit Drugs