Spontaneous Pneumomediastinum: A Rare Complication of COVID-19 Pneumonia

Abstract

A novel coronavirus was identified at the end of December 2019 as the cause of a cluster of pneumonia cases in Wuhan, China. The virus that causes Coronavirus diseases-19 ( COVID-19) is designated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The clinical manifestations of COVID -19 and complications are evolving. Cardiac, renal, neurologic complication and coagulopathy has been reported in the literature. Here we present a case of spontaneous pneumomediastinum who tested positive for COVID -19 . A 45 years old female who was admitted after a reverse transcriptase-polymerase chain reaction (RT-PCR) test-confirmed COVID-19. She was experiencing worsening dyspnea. Initial laboratory investigation showed white blood cells of 7.49 [differential: 80.5% neutrophils and 13.6% lymphocytes]. Procalcitonin was 0.12, lactate dehydrogenase was 701, ferritin was 586, fibrinogen was more than 600, D-dimer was 0.56, CRP was 9.9. Arterial blood gas showed pH 7.44, PCO2 54 mmHg, and PO2 85.7 mmHg on 85% FiO2 heated high flow nasal cannula oxygen. A chest x-ray showed bilateral interstitial and alveolar opacities. A diagnosis of acute respiratory distress syndrome (ARDS) was made. Despite maximum high flow oxygen patient continues to desaturate and the patient was started on BiPAP with 100% FiO2 with the improvement of hypoxia. The patient continued on Covid specific therapy including dexamethasone. The patient remained BiPAP dependent with intermittent heated high flow nasal cannula with positive pressure support. On the 15-day of hospitalization, the patient noted to have worsening hypoxia, emergent computed tomography angiogram(CTA) of the chest was done which revealed extensive pneumomediastinum. Esophagogram was obtained and esophageal rupture was ruled out. The patient was treated conservatively and monitored for any further complications. On day 43 patient was discharged on 2liter nasal cannula oxygen. Spontaneous pneumomediastinum (SPM) is a rare clinical entity. SPM occurs when the air leak through the small alveolar ruptures into the surrounding bronchovascular sheath. SPM also could result from air leaks from the esophageal or endobronchial rupture. The exact mechanism is unknown but the proposed mechanism is likely via the differential pressure gradient that develops between the Alveoli and lung interstitium. Barotrauma from mechanical ventilation accounts for one-third of the cases of pneumomediastinum. In our case patient was not on mechanical ventilation and esophageal rupture was ruled out by esophagogram, so we believe it is a spontaneous pneumomediastinum. We believe prolonged positive pressure ventilation could lead to rupture of the alveoli in COVID-19 pneumonia, leading to spontaneous pneumomediastinum.