Assessment of Continuous Measurement of Transcutaneous CO2 for Evaluation of Alveolar Dead Space During Exercise

Inclusion Criteria

• •Written and informed consent, and assent where required.
• •Either:
• •Patients in intensive care, conscious and in stable hemodynamic condition, who are already equipped with an arterial line for blood gas analysis (as required by the routine practice in intensive care; no arterial line shall be inserted for the purpose of this study) (Part A1)
• •Or patients/subjects scheduled for routine cardio-pulmonary exercise testing. Among these, the following patients will be included: COPD, PAH, healthy subjects, hyperventilation, chronic cardiac failure, interstitial lung diseases (ILD) (Part A2 and Part B)