ABSTRACT
Rationale: Barotrauma during mechanical ventilation more frequently occurs in COVID-19 patients than other diseases. Some previous studies reported that barotrauma was a risk factor for death;however, immortal bias due to its time-dependent nature was not considered in these studies. Therefore, we surveyed each prognosis of barotrauma whose onset was divided by time.Materials and Methods: We retrospectively reviewed intubated COVID-19 patients from March in 2020 to May in 2021. We compared 90-day survival prognosis of the barotrauma group (pneumothorax and pneumomediastinum/subcutaneous emphysema) with that of the non-barotrauma group. We also performed landmark survival analysis at day 7, 14, 21, and 28. Barotrauma occurred within 7 days on and before the landmark was considered as the exposure. The patients who were extubated before the exposure period were excluded. Additionally, we assessed the clinical data of surgically treated pneumothorax secondary to COVID-19 in our institution.Results: A total of 192 patients were included. Barotrauma occurred in 44 patients (22.9 %) (only pneumomediastinum/subcutaneous emphysema: 27 cases, only pneumothorax: 11 cases, both of them: 6 cases). The 90-day survival rate of the barotrauma group was significantly worse compared to the non-barotrauma group (47.7 % vs 82.4 %, p < 0.001). In the 7-day landmark analysis, there was no significant difference in the 90-day survival rate from the landmark between the barotrauma group and the non-barotrauma group (75.0 % vs 75.7 %, p = 0.79). On the other hand, in the 14, 21, and 28-day landmark analysis, the survival rate of the barotrauma group was significantly worse than that of the non-barotrauma group (at day 14, 41.7 % vs 69.1 %, p = 0.044;at day 21, 16.7 % vs 62.5 %, p = 0.014;at day 28, 20.0 % vs 66.7 %, p = 0.018).Pathological specimens of surgical cases showed subpleural hematoma and pulmonary cyst in the background of heterogenous lung inflammation.Conclusions: Barotrauma was a poor prognostic factor in ventilated COVID-19 patients. The impact of barotrauma after 7 days from intubation could be more important than within 7 days. Barotrauma might be an important clinical sign of lung destruction by COVID-19.