Intraoperative Measurement of Lung Elastance and Transpulmonary Pressure Using Two Different Methods

Classically lung elastance and transpulmonary pressure are measured from the difference in tidal variations of airway pressure subtracted by tidal variations i esophagus pressure divided by the tidal volume. This requires the presence of a esophageal balloon catheter which is cumbersome and costly. In this study values obtained as described above are compared to values obtained with a new method in which a stepwise increase in positive endexpiratory pressure (PEEP) is performed with a size which corresponds to the tidal volume which the patient is ventilated with. These measurements are performed in anesthetized patients prior to major surgery.