Pneumomediastinum in ARDS (acute respiratory distress syndrome) caused by COVID-19 (coronavirus disease 2019): is protective lung ventilation really a weapon to our advantage?

ABSTRACT

Introduction: In mechanically ventilated patients suffering from ARDS as a consequence of COVID-19 interstitial pneumonia, we have often noted pneumomediastinum development despite the use of protective mechanical ventilation [1]. The purpose of this study is to determine whether the incidence of pneumomediastinum in patients with COVID-19 ARDS was higher than in ARDS patients without COVID-19 and whether this difference could be attributed to barotrauma or pulmonary fragility. Methods: We divided the patients into two groups Group A (patients with ARDS from COVID-19), Group B (patients with ARDS from other causes). All patients were admitted to ICU (intensive care unit) and treated with protective mechanical ventilation-tidal volume 4-6 ml/ kg of IBW (ideal body weight), plateau pressure ≤ 28 cmH2O, driving pressure ≤ 12-14 cmH2O. Results: In group A, pneumomediastinum occurred in 8 of 59 patients(13.5%) while in group B in 1 of 59 (1.6%) (p < 0.001). Mortality was 58% in group A patients while 48% in group B patients (p = 0.32). In group A the mean of tidal volume used was 5.6 ± 0.7 ml/kg of IBW, the mean of plateau pressure 22 ± 5 cmH2O and driving pressure 11 ± 4 cmH2O. In group B the mean of tidal volume used was 5.9 ± 0.5 ml/kg of IBW, the mean of plateau pressure 23 ± 4 cmH2O and driving pressure 10 ± 3 cmH2O. Conclusions: The incidence of pneumomediastinum was approximately 8 times higher in the group of patients with COVID-19 ARDS despite the use of protective ventilation. This complication could be the consequence of greater lung fragility in patients with COVID-19 ARDS rather than in barotrauma which refers to elevated transpulmonary pressure.