Comparative analysis of standard versus prolonged prone positioning in C-ARDS: outcomes on oxygenation and respiratory mechanics

Background: The COVID-19 pandemic has led to increased prevalence of COVID-19-associated Acute Respiratory Distress Syndrome (C-ARDS) in intensive care units (ICUs). Prone positioning (PP) is recommended for managing ARDS to improve oxygenation and respiratory mechanics. However, the optimal duration of PP and its impact on ventilator-free days (VFD) and ICU mortality remains unclear. Methods: This retrospective cohort study analyzed the data of 350 C-ARDS patients intubated within 24 hours of ICU admission in the period between March 2019 and January 2023. Patients were placed in two groups based on PP duration, i.e., standard PP (SPP, 16–24 hours) and prolonged PP (PPP, 25–36 hours). The primary outcome was the ICU mortality, and secondary outcomes were VFD, changes in respiratory mechanics and oxygenation indices in pre-prone, prone and post-prone periods. Results: SPP and PPP improved the oxygenation with significant increase in the Partial pressure of Oxygen/Fraction of inspired Oxygen (PaO2/FiO2) ratio and (PaO2/FiO2) ratio/Positive End-Expiratory Pressure (PF/PEEP) values in prone period compared to the pre-prone. Not much difference in ICU mortality or VFD was observed between the groups. Subgroup analyses showed that the survivors had lower driving pressure (DP) and mechanical power (MP) compared to those of the non-survivors. Conclusions: Both SPP and PPP improved the oxygenation, however no survival advantage was observed with prolonged prone sessions. PP is effective for lung-protective ventilation, and its duration should be adjusted based on the patient-specific factors. Further studies are required to optimize the PP durations for managing C-ARDS. Clinical Trial Registration: ClinicalTrials.gov, Registration ID: NCT06530095.