Clinical characteristics of pneumothorax and pneumomediastinum in mechanical ventilated patients with coronavirus disease 2019: a case series

Background Pneumothorax (PTX) and pneumomediastinum (PM) have been reported as potential complications in patients with coronavirus disease 2019 (COVID-19); however, their risk factors and etiology remain unknown. Herein, we investigated the clinical characteristics of mechanically ventilated patients with COVID-19 with PTX or PM.Methods We examined patients with severe COVID-19 requiring mechanical ventilation who were admitted to the intensive care unit of a tertiary-level emergency medical center in Tokyo, Japan between April 1, 2020. and October 31, 2021. We collected and analyzed the clinical characteristics of the patients who presented with either PTX or PM during mechanical ventilation.Results During the study period, a total of 165 patients required mechanical ventilation, and 15 patients with PTX/PM during mechanical ventilation were selected. Three patients with obvious causes were excluded, and the remaining 12 patients were analyzed (7.3%). The mortality rate in these patients was as high as 50%, demonstrating the difficulty of treatment in the presence of PTX/PM. PTX/PM occurred 14.5 days after intubation. A peak pressure of > 30 cmH2O was only apparent in one patient, suggesting that high positive pressure ventilation may be less involved than mentioned in the literature. In addition, the inspiratory effort was not strong in our group of patients. (P0.1 was 2.1 cm H2O [1.0-3.8]).Conclusion Various factors are associated with the development of PTX/PM in patients on mechanical ventilation for COVID-19. We did not find a strong correlation between PTM/PM and barotrauma or strong inspiratory efforts, which have been identified as potential causes in previous studies.