Effects of the prone position on arterial blood gas analysis and respiratory parameters of acute respiratory distress syndrome patients: An observational retrospective study

Objective: To investigate the effect of the first prone position on arterial blood gas analysis and respiratory parameters of acute respiratory distress syndrome (ARDS) patients with and without COVID.Methods: This study was conducted retrospectively with 22 COVID-ARDS and 22 non-COVID ARDS patients, who were placed in a prone position for at least 16 hours on the first day at the intensive care unit admission, and arterial blood gas analysis was taken in the pre-prone, prone and post-prone periods.Results: PaO2 were significantly increased in the pre-prone vs. prone comparison in both groups, but the increase in the PaO2/FiO(2 )ratio was not significant. In comparing the pre-prone vs. post-prone PaO2/FiO(2) ratios, there was a significant difference only in the non-COVID ARDS group.Conclusions: The improved oxygenation provided by prone positioning is more permanent with the "post-prone effect" in non-COVID ARDS patients. This can be attributed to the differences in the pathogenesis of the two ARDS types.