Hamman Syndrome with a Rare Feature of Pneumorrhachis - An Unusual Complication of Polysubstance abuse and e-vaping

Hamman syndrome is defined as dissection of air in mediastinum and skin fascia usually due to increased intrathoracic pressure. The air leak tends to make its way into pleural and pericardial layers; however, in rare instances air can also dissect into epidural spaces, regarded as pneumorrhachis. We present a case of a young male with a history of polysubstance abuse and e-vaping, who presented with symptoms of altered mental status. Given the concerning physical examination, a computed tomography of the chest was undertaken, which showed pneumothorax, pneumomediastinum and pneumorrhachis. The patient was closely monitored in the intensive care unit and improved after symptomatic management. The symptoms of pneumorrhachis depend on the volume and location of air in intracranial and intraspinal space. Although asymptomatic in our case, it is crucial for clinicians to be aware that pneumorrhachis with Hamman syndrome can potentially cause neurological deficits and cardiopulmonary arrest in severe cases due to increased intraspinal and intracranial hypertension, emphasising the need for close monitoring.

Learning points: Elevated intrathoracic pressure generated by deep inhalation of an aerosolised product is one of the triggers of air dissection in pleural, pericardial, and mediastinal regions. In rare instances, air can also translocate into intracranial and intraspinal spaces, which is referred to as pneumorrhachis.Mostly asymptomatic, pneumorrhachis has the potential to develop acute neurological deficits due to increased intracranial and intraspinal pressure, validating the need for acute monitoring.Most cases of pneumorrhachis are managed conservatively. However, severe cases warrant decompression or high concentrations of oxygen administration to facilitate air absorption.