LAUSR

potential for lung recruitment (as the recruitment-to-inflation ratio) in COVID-19 ARDS. The researchers found that lung recruitability was generally poor on the first day of observation but increased by alternating the prone and supine positions (8). This can be easily explained by the appearance of basilar consolidation over the course of COVID-19 ARDS. This consolidation accounts for 13–53% of the CT patterns, depending on when the scan is performed; the later the CT scan, the more frequent the consolidation (9, 10). In the present study, the predominant pattern in COVID-19 ARDS was diffuse ground-glass opacity, together with alveolar consolidation in about 60% of cases. This consolidation might be explained by the long median (IQR) time interval between the onset of symptoms and orotracheal intubation (10 [7–15] d) in our study population. Other studies have reported similar findings, but we cannot rule out the possible occurrence of “patient self-inflicted lung injury” due to excessive breathing efforts and delayed intubation (4, 7). Our study had some important limitations. First, the study population was small and we did not prespecify the target sample size. Second, we only assess basic respiratory mechanical variables; the comparison of advanced parameters (such as transpulmonary pressures or ventilation–perfusion mismatches) might have revealed additional intergroup differences.