A 14-year-boy presented to the emergency department with a chief complaint of chest discomfort and shortness of breath after running 1600 m (1 mile) on an asphalt track during physical education class at school 4 hours before presentation. The patient stated that he completed the run in 6 minutes, 8 seconds. The patient noted no adverse weather or ambient pressure change.
The patient had no allergies, was taking no medications, and had no notable medical or surgical history. The patient denied any history of asthma, reactive airway disease, SPM, or spontaneous pneumothorax. The patient also denied any history of similar symptoms after exercise. The patient’s immunizations were current, and he denied alcohol and other illicit drug use. Although the patient never smoked cigarettes, he was exposed to secondhand smoke from his father. The patient had no prior hospitalizations.
Review of systems was positive for shortness of breath and chest discomfort. His vital signs at presentation were a temperature of 98.7°F, a pulse rate of 77/min, a blood pressure of 122/62 mm Hg, and a respiratory rate of 20/min. His oxygen saturation level while breathing room air was 100%. The patient’s height was 185 cm; weight, 54 kg; and body mass index, 16.9— placing him in the 60th percentile for weight and in the 99th percentile for height for his age according to US Centers for Disease Control and Prevention growth charts.
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The patient was in no acute distress, and results of his physical examination were initially unremarkable with no evidence of neck, back, or chest trauma. The lungs were clear throughout bilaterally. The results of both the cardiac examination and osteopathic structural examination were unremarkable. No pectus deformity was noted. Aside from the patient’s long height and thin build, no marfanoid features were noted.
Results of an electrocardiogram were normal. Because the patient complained of persistent chest discomfort and shortness of breath, chest radiographs with posterior-anterior and lateral views were obtained and were notable for pneumomediastinum with air tracking along the mediastinal borders of the chest (
Figure 1) and around the pulmonary artery and aorta (
Figure 2).
The patient was admitted to the pediatric service for observation and pain control, and he received sup ple-mental oxygen to facilitate regular functional residual capacity. After radiologic and clinical stability was demon-strated, he was discharged the following afternoon. A second set of radiographs obtained 7 days after discharge showed complete resolution of the patient’s pneumomediastinum.