Enhanced Benefits of Prone Positioning Combined with Lung Recruitment Maneuver in Patients with COVID-19 and Non-COVID-19 ARDS: A Secondary Analysis of a Randomized Clinical Trial

<b>Background:</b> Early reports highlighted unique features of COVID-19-associated ARDS. The combination of prone position (PP) and positive end-expiratory pressure (PEEP)-induced lung recruitment maneuver (LRM) has demonstrated efficacy in enhancing oxygenation and improving outcomes in patients with ARDS, but it remains unknown whether there is a difference between COVID-19 ARDS and non-COVID-19 ARDS. <b>Method:</b> This study is a secondary analysis of a previously conducted randomized controlled trial. Patients with moderate to severe ARDS were consecutively enrolled during the study period (June-December 2023). After initiation of PP, patients received a PEEP-induced LRM followed by 12 h of daily PP. The interventions were repeated at least three times over the subsequent 3 days. Clinical outcomes, respiratory mechanics, and electrical impedance tomography (EIT) results were evaluated. <b>Results:</b> Twenty-eight patients were included in the final analysis, half of whom were infected with COVID-19 (50%). The PEEP-induced LRM led to greater improvement in oxygenation among COVID-19 ARDS than non-COVID-19 ARDS (∆PaO₂/FiO₂ ratio 90.5 mmHg vs. 65.5 mmHg, <i>p</i> < 0.05). Based on EIT measurement, compared with the non-COVID-19 ARDS group, PEEP-induced LRM resulted in a greater increase in ventilation distribution, mainly in the dorsal regions of interest 4 (ROI 4) ventilation distribution (∆ROI4 4.5% vs. 1.0%, <i>p</i> = 0.01) and in dorsal regional ventilation (∆dorsal regional ventilation 10.0% vs. 5.5%, <i>p</i> = 0.04) in the COVID-19 ARDS group. <b>Conclusions:</b> Compared to typical ARDS, PEEP-induced LRM combined with PP may be more effective in enhancing oxygenation in COVID-19-related ARDS.