Cannabinoid hyperemesis syndrome complicated by pneumomediastinum: implications for pediatrics

Background. Cannabinoid hyperemesis syndrome / CHS (prolonged and frequent use of high-dose cannabis) in the pediatric population has been increasingly reported over the last decade. CHS can lead to life-threatening complications such as pneumomediastinum, which warrant careful consideration for surgical intervention. Case Presentation. A 17-year-old female with no significant past medical history presented to the emergency department with abdominal, chest and back pain (worse with deep inspiration), nausea, and vomiting for 24 hours. Upon further history, the patient reported a similar episode six months ago, being a cannabis smoker (at least once a day) in the last two years. Chest X-ray revealed a subtle abnormal lucency along the anteroposterior window and anterior mediastinum, consistent with a small amount of pneumomediastinum without any other acute intrathoracic abnormalities. Follow-up chest computed tomography with contrast showed multiple foci of air within the anterior and posterior mediastinum tracking up to the thoracic inlet. There was no evidence of contrast extravasation; however, small esophageal perforation could not be excluded. Given uncomplicated pneumomediastinum (without frank contrast extravasation) the patient was treated medically with piperacillin-tazobactam, metronidazole, and micafungin for microbial prophylaxis; hydromorphone for pain control; as well as with pantoprazole, ondansetron, and promethazine. Nutrition was provided via total parenteral nutrition. The evolution was favorable (no signs of occult esophageal perforation occurred), being advanced to a soft diet on hospital day eight, solid food diet on day nine, at which point antibiotics were discontinued, and the patient was subsequently discharged. Conclusion. CHS in increasingly encountered in the pediatric setting due to rising prevalence of cannabis use. The management of CHS and potentially life-threatening complications such as pneumomediastinum should be given careful consideration. Pneumomediastinum can be a harbinger of esophageal perforation that may warrant urgent surgical intervention.