Chronic Heart Failure, Healthy, Hyperventilation Syndrome, Lung Diseases, Interstitial, Pulmonary Arterial Hypertension, Pulmonary Disease, Chronic Obstructive
Conditions
Keywords
transcutaneous PtCO2, dead space, exercise test
Brief summary
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: * intensive care patients, equipped, for their routine clinical care, with an arterial line; this allows for a precise timed comparison between PaCO2 and PtCO2 readouts; * routine exercise test, where blood gas evaluation is done essentially by means of arterialized earlobe capillary sampling. 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)
Interventions
OTHERsimultaneous determination of PaCO2 and PtCO2
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
OTHERExercise test
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
Sponsors
Centre Hospitalier Metropole Savoie
Study design
Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
OTHER
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
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)
Exclusion criteria
* Non-French speaking patients/subjects * Unstable hemodynamics * Local cutaneous lesion or infection * Arterial disease such as fistula * Women with the following condition: pregnancy, breast feeding * Persons deprived of liberty (according to article L1121-5 to L1121-8 of the French Public Health Code)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change from baseline of Pt CO2 (transcutaneous CO2 partial pressure) measurement together with PaCO2 (arterial partial CO2 pressure) | at rest and during exercise/hyperventilation: 30 secondes, 1 minute, 1 ½ minute 2, 2 ½ , 3 , 4, 5 and 10 minutes. | 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 |
| 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 | continuous measurement: from rest throughout exercise test ( beginning of test, to maximum load (5-10 minutes), then throughout 5 minutes recovery. | 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. |
Countries
France
Outcome results
None listed