Spontaneous pneumomediastinum: two contrasting cases that highlight key aspects of management.

To cite: Kelham MD, Nghiem AZ, Goundry AL. BMJ Case Rep Published online: [please include Day Month Year] doi:10.1136/ bcr-2014-208005 DESCRIPTION A 24-year-old woman presented with a 1-day history of neck tightness following a 10-day history of cough and left-sided chest pain. Her CT is shown in figure 1, which reveals a pneumomediastinum, pneumothorax of the left lung and extensive subcutaneous emphysema that was clinically palpable. After discussion with the regional cardiothoracic unit, given the extent of the pneumothorax, she was managed with a chest drain and high flow oxygen. She was discharged on day 6 with chest radiography confirming resolution of the pneumomediastinum, pneumothorax and emphysema. Figure 2 was taken from a 23-year-old man who presented with lower central chest and epigastric pain after a prolonged course of vomiting. On examination he was tender in the epigastrium. Chest CT revealed a pneumomediastinum but no other abnormalities. The history and the CT findings prompted an urgent contrast swallow in order to exclude Boerhaave’s syndrome. After the contrast swallow was reported as normal and as the patient remained stable he was discharged home on day 6 with outpatient follow-up. Spontaneous pneumomediastinum (SPM) is an uncommon condition defined by air in the mediastinum without any obvious precipitating cause such as trauma or instrumentation. Pathophysiology is based on the Macklin effect whereby increased intrathoracic pressure leads to alveolar rupture and subsequent air dissection into the mediastinum and subcutaneous tissue. This may be due to coughing, vomiting or inhalational drug use. Case series suggest SPM is generally associated with a benign clinical course.