Fig. 2From: Capnodynamic monitoring of lung volume and blood flow in response to increased positive end-expiratory pressure in moderate to severe COVID-19 pneumonia: an observational studyChanges in end-expiratory lung volume by capnodynamic monitoring (∆\({\text{EELV}}_{{{\text{CO}}_{2} }}\)) and the recruited lung volume (∆Volrec) assessed based on the exhaled tidal volume at the rapid reduction from PEEPhigh to PEEPlow as previously described [19]. The correlation is shown as Pearson’s regression (solid line) with the 95% confidence intervals (dashed lines)Back to article page