Pneumomediastinum in a patient with COVID-19 due to diffuse alveolar damage.

A 74-year-old man with COVID-19 was admitted and experienced progressive dyspnoea while receiving supplemental oxygen via high-flow nasal cannula (HFNC). A CT of the thorax showed a pneumomediastinum. The HFNC was temporally interrupted, since it was uncertain whether the positive end-expiratory pressure of the HFNC could be the cause of the pneumomediastinum. After restart of the HFNC, there was no increase of symptoms. We suggest that the pneumomediastinum was the result of COVID-19-related alveolar damage, and not due to the use of HFNC. This observation is relevant since HFNC is often used in the treatment of severe COVID-19 pneumonia.