Study design
This study conducted a retrospective analysis of 289 critically ill COVID-19 patients who received invasive mechanical ventilation in the ICU of three general hospitals in Taizhou City, Zhejiang Province, from December 1, 2022, to February 1, 2023. Among these cases, 157 were treated with PP, while 132 were not.
The exclusion criteria for the PP group included [7-9]: (1) incomplete case records (67 cases); (2) PP duration less than 12 hours (10 cases); (3) PP treatment initiated before admission to the ICU (1 case); (4) prior extracorporeal membrane oxygenator treatment before PP (1 case). The non-PP group (78 cases) was selected through 1:1 propensity score matching (PSM) analysis with the PP group (78 cases) based on age, sex, underlying disease, and Sequential Organ Failure Assessment (SOFA) score(Fig.1).
Among the PP group, 21 cases underwent only one PP cycle, 23 cases underwent two PPcycles, 15 cases underwent three PP cycles, and 19 cases underwent more than three PP cycles. All patients in PP group were diagnosed with COVID-19 and required invasive mechanical ventilation before the first PP. This study specifically examined the initial three instances of PP. The commencement of PP occurred at 2.0 (2.0, 5.0) days after admission to the ICU. Furthermore, each PP lasting for a median duration of 18.0 (16.0, 24.5) hours and an interval between each PP of 8.8 (6.0, 26.9) hours.
None of them developed life-threatening complications during PP (one case exhibited petechiae on both sides of the abdomen, another case presented petechiae on the left wrist, and two cases experienced facial swelling). This study was approved by the Medical Ethics Committee of Taizhou Hospital, Zhejiang Province, China (Approval NO.: K20230116).