Transcutaneous Partial Oxygen and Carbon Dioxide Pressures Compared With Blood Gas Values

The sensor will be attached to four anatomical positions (thoracic left and right; abdominal left and right), starting with the left thoracic position followed by 4-hourly clockwise position rotation. In case of severe oedema, the ear lobes will be used as anatomical measurement sites and changes to the contralateral ear lobe are made every 4 hours.