Measurement of Lung Elastance and Transpulmonary Pressure Using Two Different Methods (Lungbarometry)

Measurement of Lung Elastance and Transpulmonary Pressure Using Two Different Methods (Lungbarometry)

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 of the lung volume increase which corresponds to the tidal volume which the patient is ventilated with. The measurements are performed in sedated and mechanically ventilated patients in the intensive care unit.

Classically lung elastance and transpulmonary pressure are measured from the difference in tidal variations of airway pressure subtracted by tidal variations in esophageal pressure divided by the tidal volume (Method 1). This requires the presence of a esophageal balloon catheter which is cumbersome and costly.

In this study values obtained as described in Method 1 above are compared to values obtained with a new method (Method 2) in which a PEEP-step is performed with a size of the lung volume increase which corresponds to the tidal volume which the patient is ventilated with. Measurements using Method 1 and 2 are performed in sedated and mechanically ventilated patients in the intensive care unit.

Inclusion Criteria:

Mechanically ventilated patients in the intensive care unit

Exclusion Criteria:

Patients with chronic obstrucive lung disease