Low PEEP Mechanical Ventilation and PaO/FiO Ratio Evolution in COVID-19 Patients.

Invasive mechanical ventilation (IMV) is the standard treatment in critically ill COVID-19 patients with acute severe respiratory distress syndrome (ARDS). When IMV setting is extremely aggressive, especially through the application of high positive-end-expiratory respiration (PEEP) values, lung damage can occur. Until today, in COVID-19 patients, two types of ARDS were identified (L- and H-type); for the L-type, a was supposed to be preferred, but data are still missing. The aim of this study was to evaluate if a clinical management with lower PEEP values in critically ill L-type COVID-19 patients was safe and efficient in comparison to usual standard of care. A retrospective analysis was conducted on consecutive patients with COVID-19 ARDS admitted to the ICU and treated with IMV. Patients were treated with a adapted to BMI: PEEP 10 cmHO if BMI < 30 kg m, PEEP 12 cmHO if BMI 30-50 kg m, PEEP 15 cmHO if BMI > 50 kg m. Primary endpoint was the PaO/FiO ratio evolution during the first 3 IMV days; secondary endpoints were to analyze ICU length of stay (LOS) and IMV length. From March 2 to January 15, 2021, 79 patients underwent IMV. Average applied PEEP was 11 ± 2.9 cmHO for BMI < 30 kg m and 16 ± 3.18 cmHO for BMI > 30 kg m. During the first 24 h of IMV, patients' PaO/FiO ratio presented an improvement (<0.001; CI 99%) that continued daily up to 72 h (<0.001; CI 99%). Median ICU LOS was 15 days (10-28); median duration of IMV was 12 days (8-26). The ICU mortality rate was 31.6%. Lower PEEP strategy treatment in L-type COVID-19 ARDS resulted in a PaO/FiO ratio persistent daily improvement during the first 72 h of IMV. A could be beneficial in the first phase of ARDS in critically ill COVID-19 patients.