ABSTRACT
Several studies have evaluated the impact of radiological phenotyping in the management of COVID-19 pneumonia (G. Scioscia et al. Arch Bronconeumol (Engl Ed). 2021 Jul 28). Moreover, among the various procedures, the prone position (PP) appears to be effective in improving alveolar gas exchange. Therefore, we have tested the efficacy of PP in different COVID-19 radiological phenotypes (PH). The study was conducted on COVID-19 patients admitted in our Unit between November 2020 and April 2021. The patients with a PaO2/FiO2 (P/F) <= 200 mmHg on blood gas analysis underwent PP cycles. In relation to PP ability, they were divided into two groups (Prone and Supine) and the groups were then compared. We enrolled 60 patients (29 Prone and 22 Supine). Of all patients, we calculated the post-PP P/F gain, resulting in 51.7+/-30.2 mmHg in PH1, 50.3+/-24.2 in PH2 and 55.0+/-19.7 mmHg in PH3. Although there were no significant differences in mortality rates between phenotypes, a post-PP gain >=20% seems to be a safety cut-off of response to PP. Hence, 83.3% PH2, 66.7% PH1 and 55% PH3 were identified as "responders" In conclusion, our findings suggest that PP is a procedure that should be performed;it improves gas exchange even if it shows different efficacy based on the radiological phenotype. Therefore, a gain of >=20% PaO2/FiO2 post-PP could be considered a discriminating marker of efficacy of this therapeutic approach.