Fig. 2

Validation test at different esophageal catheter-filling volumes. Panels (a) and (c): Paw and Pes over time, during a single mechanical respiratory breath and an end-expiratory occlusion maneuver with chest compressions. Arrows refer to the start of the occlusion maneuver. Panels (b) and (d): Pes/Paw relative changes during the end-expiratory occlusion maneuver. Panels (a) and (b) correspond to an esophageal balloon catheter filling of 0.5 ml, while panels (c) and (d): correspond to a filling of 2.5 ml. The slope of the Pes/Paw relationship was 0.48 with an injected volume of 0.5 ml (panel b) and 1.02 with an injected volume of 2.5 ml (panel d). Paw airway pressure, Pes esophageal pressure