Non-invasive measurement of lung compliance and transpulmonary pressure during controlled ventilation

Measurement of the lung compliance is important in personalizing mechanical
ventilation on the ICU. The traditional methods of measuring lung compliance *
using air-filled endo-esophageal balloons * is widely applied, but is invasive
and is prone to systematical errors. A newly proposed volumetric method is
non-invasive and should be more precise, but the method has not been validated.

The objective of this study is to determine the agreement between the
traditional endo-esophageal balloon method and newly proposed volumetric method
of determining lung compliance.

This is a prospective observational study designed to assess the agreement
between two methods.

An endo-esophageal balloon catheter is placed. The subject undergoes detailed
measurements during a pre-determined protocol, in which PEEP and tidal volume
is subject to regular changes. The estimated duration is 1.5 hours. Peak
pressure and tidal volume are kept below and .
This study can only be performed in sedated patient receiving controlled
mechanical ventilation. The cohort should include both lung-healthy subjects
and subjects with lung injury. Only ICU patients fulfil these criteria.
The risks of this study encompass the placement of the endo-esophageal
catheter. The catheter is very similar to a normal gastric feeding catheter.
Risk of injury during placement is deemed small. Mechanical ventilation with
high peak pressures or high tidal volumes is deemed detrimental, if applied for
a long time. During his study, the subject will be ventilated with high peak
pressures (max. 45 cmH2O) and tidal volumes (max. 12 ml/kg Ideal Body Weight)
for short periods of time only.