An interventional study of simultaneous determination of PaCO2 and PtCO2 and Hyperventilation test in Pulmonary Disease, Chronic Obstructive, Lung Diseases, Interstitial and Chronic Heart Failure, sponsored by Centre Hospitalier Metropole Savoie. Completed at 4 sites in France. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-10-07.
Sponsored by Centre Hospitalier Metropole Savoie · Not applicable, Interventional, and Other
The study aim is to monitor, during exercise tests carried out in various conditions, the alveolar dead space, by means of continuous transcutaneous measurement of Pt CO2, which would be used as a surrogate for arterial PaCO2. Validity of this measurement needs to be assessed against arterial sampling (either arterial, or arterialized capillary), especially with regards to the lag time required by the CO2 diffusion from the arterial compartment (PaCO2) to the cutaneous one (PtCO2), in particular when rapid changes of CO2 might be induced by exercise.
The evaluation will be done in 2 different settings:
Following assessment of validity of the measurement (and the lag time PaCO2-PtCO2 which might be necessary to introduce as a correction), evolution of dead space during excise test will be tested in different conditions: Healthy subjects, patients with Chronic Obstructive Pulmonary Disease (COPD), chronic heart failure (CHF), hyperventilation, Pulmonary artery hypertension (PAH), or interstitial lung disease (ILD)
4,131 studies on the registry are indexed under Pulmonary Disease, Chronic Obstructive; 697 are open to participants now.
This study's enrollment of 140 is above the median of 70 across 2,926 interventional studies indexed under Pulmonary Disease, Chronic Obstructive.
Browse Pulmonary Disease, Chronic Obstructive studies →Centre Hospitalier Metropole Savoie is the lead sponsor of 22 studies on the registry; 9 are open to participants now.
Counted across the registry records on this site, refreshed daily.
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)
Exclusion Criteria:
Patient in intensive care (n=10): in patients in the intensive care unit of the Centre Hospitalier Metropole Savoie (Chambéry, France), where repeated arterial blood gas analysis is routinely performed (Patients equipped for their usual care with an arterial catheter, enabling repeated arterial blood gas determination ). PaCO2 and Pt CO2 will be measured simultaneously at rest, and during conditions inducing PaCO2 modifications (ventilator settings modifications, or exercise as per routine rehabilitation) Comparison will be done between arterial PaCO2 and PtCO2
Other: simultaneous determination of PaCO2 and PtCO2
Healthy subjects performing a voluntary hyperventilation, in the laboratory room where routine exercise testing is usually done. Comparison will be done between arterialized PaCO2 and PtCO2, at rest, and during an induced voluntary hyperventilation.
Other: Hyperventilation test · Other: Exercise test
Subjects, referred for exercise diagnostic testing, and whose results indicate normal cardiac and pulmonary exercise physiology. Measurement, throughout these exercise tests, of the alveolar dead space, and its kinetics, up to peak VO2, then during recovery, in the different conditions listed above. Alveolar dead space will be calculated using the continuous Pt CO2 values observed, and also with some intermittent PaCO2 measurement, done as per routine modus operandi (arterialized earlobe capillary drawn at rest, at ventilatory threshold, and at peak exercise). The values measured through PtCO2 and PaCO2 will be compared at these 3 time points.
Other: Exercise test
Measurement, throughout these exercise tests, of the alveolar dead space, and its kinetics, up to peak VO2, then during recovery, in the different conditions listed above. Alveolar dead space will be calculated using the continuous Pt CO2 values observed, and also with some intermittent PaCO2 measurement, done as per routine modus operandi (arterialized earlobe capillary drawn at rest, at ventilatory threshold, and at peak exercise). The values measured through PtCO2 and PaCO2 will be compared at these 3 time points.
Other: Exercise test
Measurement, throughout these exercise tests, of the alveolar dead space, and its kinetics, up to peak VO2, then during recovery, in the different conditions listed above. Alveolar dead space will be calculated using the continuous Pt CO2 values observed, and also with some intermittent PaCO2 measurement, done as per routine modus operandi (arterialized earlobe capillary drawn at rest, at ventilatory threshold, and at peak exercise). The values measured through PtCO2 and PaCO2 will be compared at these 3 time points.
Other: Exercise test
Measurement, throughout these exercise tests, of the alveolar dead space, and its kinetics, up to peak VO2, then during recovery, in the different conditions listed above. Alveolar dead space will be calculated using the continuous Pt CO2 values observed, and also with some intermittent PaCO2 measurement, done as per routine modus operandi (arterialized earlobe capillary drawn at rest, at ventilatory threshold, and at peak exercise). The values measured through PtCO2 and PaCO2 will be compared at these 3 time points.
Other: Exercise test
Measurement, throughout these exercise tests, of the alveolar dead space, and its kinetics, up to peak VO2, then during recovery, in the different conditions listed above. Alveolar dead space will be calculated using the continuous Pt CO2 values observed, and also with some intermittent PaCO2 measurement, done as per routine modus operandi (arterialized earlobe capillary drawn at rest, at ventilatory threshold, and at peak exercise). The values measured through PtCO2 and PaCO2 will be compared at these 3 time points.
Other: Exercise test
Measurement, throughout these exercise tests, of the alveolar dead space, and its kinetics, up to peak VO2, then during recovery, in the different conditions listed above. Alveolar dead space will be calculated using the continuous Pt CO2 values observed, and also with some intermittent PaCO2 measurement, done as per routine modus operandi (arterialized earlobe capillary drawn at rest, at ventilatory threshold, and at peak exercise). The values measured through PtCO2 and PaCO2 will be compared at these 3 time points.
Other: Exercise test
Patients in intensive care, equipped, for their routine clinical management, with an arterial catheter blood line, will have a simultaneous determination of PaCO2 and PtCO2: * 1\) at rest; 2 arterial CO2/PtCO2 determinations will be carried out, 10 minutes apart * 2\) During the muscular exercise part of their routine rehabilitation program (whatever it might be, limbs active mobilization, walking, etc...) : several arterial /PtCO2 samples will be collected during the first minutes of their muscular routine: 30 sec, 1 minute, 1 ½ minute, 2, 2 ½ , 3, 4, 5 minutes, 10 minutes (end of exercise). This will generate several couples of blood/transcutaneous CO2 determinations
Repeated pairs of PtCO2 and PaCO2 (through arterialized capillary sampling), will be measured at the following timing: rest (0), then 30 sec post beginning of hyperventilation (breathing with accelerated frequency e.g. 30/min), 1 minute, 1 ½ minute 2, 2 ½ , 3, , 4, 5 minutes; recovery of this hyperventilation will be followed, for 5 minutes, with the PtCO2, during 3 minutes
an exercise test, according to the routine protocol used in the clinic: initial phase of 3 minutes gentle pedaling (10 to 50 watts, according to subject capabilities), then stepwise increase in the workload, by increments of 20-40 watts every minute, until maximum tolerated workload (VO2max). Repeated pairs of PtCO2 and PaCO2 (through arterialized capillary sampling), will be measured at the following timing: rest -10 minutes, 0, then 30 sec post beginning of exercise, 1 minute, 1 ½ minute 2, 2 ½, 3 minutes, then 3 ½ minutes, then at mid-point of every step increase in workload, until maximum tolerated workload. Recovery will be followed with the PtCO2, for 5 minutes
Change from baseline of Pt CO2 (transcutaneous CO2 partial pressure) measurement together with PaCO2 (arterial partial CO2 pressure)
Part A: serial simultaneous measurements of Pt CO2 (transcutaneous CO2 partial pressure), and PaCO2 (arterial partial CO2 pressure), done 1. during exercise 2. during voluntary hyperventilation
Time frame: at rest and during exercise/hyperventilation: 30 secondes, 1 minute, 1 ½ minute 2, 2 ½ , 3 , 4, 5 and 10 minutes.
Change from baseline by means of continuous measurement of alveolar dead space (VD/VT=(PaCO2-PECO2) /PaCO2), expressed as a percentage from 0% to 100 %) , during exercise test, in different clinical settings
Part B: change from baseline with continuous alveolar dead space ( (VD/VT=(PaCO2-PECO2) /PaCO2), expressed as percentage from 0 to 100%) variation measurement, during exercise and recovery, in: * healthy subject * different patient categories: COPD at different stages, pulmonary artery hypertension, hyperventilation syndrome, cardiac failure, Interstitial Lung Disease). Establish patterns seen in these different conditions.
Time frame: continuous measurement: from rest throughout exercise test ( beginning of test, to maximum load (5-10 minutes), then throughout 5 minutes recovery.
Plan to share: No
No publications or documents are linked to this record.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is completed, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Pulmonary Disease, Chronic Obstructive→
Centre Hospitalier Metropole Savoie