Diagnosis: Pneumomediastinum
The PA and lateral view CXRs revealed the presence of retrosternal air, suggesting the patient had pneumomediastinum. A computed tomography (CT) scan of the chest also showed retrosternal air (FIGURE 2A AND 2B, arrows) and confirmed this diagnosis. To rule out esophageal perforation, the team ordered Gastrografin and barium swallow studies. The patient was kept NPO until both studies were confirmed to be negative.
Pneumomediastinum—the presence of free air in the mediastinum—can develop spontaneously (as was the case with our patient) or in response to trauma. Common causes include respiratory diseases such as asthma, and trauma to the esophagus secondary to mechanical ventilation, endoscopy, and excessive vomiting.1 Other possible causes include respiratory infections, foreign body aspiration, recent dental extraction, diabetic ketoacidosis, esophageal perforation, barotrauma (due to activities such as flying or scuba diving), and use of illicit drugs.1
Patients with pneumomediastinum often complain of retrosternal, pleuritic pain that radiates to their back, shoulders, and arms. They may also have difficulty swallowing (globus pharyngeus), a nasal voice, and/or dyspnea. Physical findings can include subcutaneous emphysema in the neck and supraclavicular fossa as manifested by Hamman’s sign (a precordial “crunching” sound heard during systole), a fever, and distended neck veins.1