Recreational nitrous oxide inhalation as a rare cause of spontaneous pneumomediastinum.

A 17-year-old girl presented to the A&E department with significant neck swelling with associated chest, neck and throat pain. She reported recreational inhalation of nitrous oxide and ingestion of MDMA (3,4-methylenedioxy-methamphetamine) in the preceding hours. There was no history of trauma or vomiting. Clinical examination revealed extensive subcutaneous emphysema. There was no airway compromise. A chest X-ray suggested the presence of a pneumomediastinum. Subsequent CT of the thorax confirmed an anterior pneumothorax and a pneumopericardium. The patient was admitted for observation and intravenous antibiotics. Further investigations ruled out an oesophageal perforation. The patient was discharged following a period of clinical stability and has since made an uneventful recovery. MDMA ingestion has been cited as a rare cause of spontaneous pneumomediastinum in a series of case reports. In this case, it is likely that the inhalation of nitrous oxide contributed to the development and expansion of a pneumomediastinum. 2015 BMJ Publishing Group Ltd.