Pulmonary Diffusing Capacity During Acute Exercise in Patients With COPD

Study Overview
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Brief Summary
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The combined measurement of the pulmonary diffusing capacity to carbon monoxide (CO) and nitric oxide (NO) (DLCO/NO) during exercise may be a useful physiological measure of alveolar-capillary reserve in patients with Chronic obstructive pulmonary disease (COPD). The present study investigated the test-retest reliability of DLCO/NO-based metrics.

Detailed Description
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The combined measurement of the pulmonary diffusing capacity to carbon monoxide (CO) and nitric oxide (NO) (DLCO/NO) has recently been standardised and validated for clinical use. It is thus ideal for assessing acute changes in pulmonary diffusing capacity and its components during various physiological manoeuvres. These changes are thought to involve acute changes in pulmonary perfusion and are notably relevant for patients with chronic obstructive pulmonary disease (COPD), in which they may be related to exertional dyspnoea. The aim of the present study is to investigate the effects of acute exercise on pulmonary diffusing capacity, and to determine the day-to-day repeatability of such assessments.

Official Title
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Pulmonary Diffusing Capacity to Nitric Oxide and Carbon Monoxide During Exercise in Patients With Chronic Obstructive Pulmonary Disease: a Test-retest Reliability Study

Conditions
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Chronic Obstructive Pulmonary Disease

Intervention / Treatment
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* Diagnostic Test: Acute exercise


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Chronic obstructive pulmonary disease (GOLD II + III) Exclusion Criteria: Known heart disease Pregnancy Disease within two weeks prior to inclusion

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Acute exercise<br>Pulmonary diffusing capacity using the DLCO/NO technique is assessed at rest and during exercise (60% of maximal workload on a bicycle ergometer) | Diagnostic Test: Acute exercise<br>* The measurement will be repeated within one to seven days.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rest-to-exercise change in DLNO | The physiological change from rest to exercise in DLNO obtained using the combined DLCO/NO technique with a 5-sec breathhold. | Measured at day 1 and day 2 | 
| Rest-to-exercise change in DLCOc | The physiological change from rest to exercise in DLCOc obtained using the combined DLCO/NO technique with a 5-sec breathhold. | Measured at day 1 and day 2 | 
| Rest-to-exercise change in DM | The physiological change from rest to exercise in DM obtained using the combined DLCO/NO technique with a 5-sec breathhold. | Measured at day 1 and day 2 | 
| Rest-to-exercise change in VC | The physiological change from rest to exercise in VC obtained using the combined DLCO/NO technique with a 5-sec breathhold. | Measured at day 1 and day 2 | 
| Rest-to-exercise change in VA | The physiological change from rest to exercise in VA obtained using the combined DLCO/NO technique with a 5-sec breathhold. | Measured at day 1 and day 2 | 
| Smallest real difference (SRD) for Diffusion capacity for DLNO at rest | SRD with 95 % confidence intervals (95% CI) for DLNO at rest | Measured at day 1 and day 2 | 
| SRD for DLNO during exercise | SRD with 95% CI for DLNO during exercise | Measured at day 1 and day 2 | 
| SRD for Diffusion capacity for carbon monoxide (DLCOc) at rest | SRD with 95% CI for DLCOc at rest | Measured at day 1 and day 2 | 
| SRD for DLCOc during exercise | SRD with 95% CI for DLCOc during exercise | Measured at day 1 and day 2 | 
| SRD for membrane diffusing capacity (DM) at rest | SRD with 95% CI for DM at rest | Measured at day 1 and day 2 | 
| SRD for DM during exercise | SRD with 95% CI for DM during exercise | Measured at day 1 and day 2 | 
| SRD for Pulmonary blood volume (Vc) at rest | SRD with 95% CI for Vc at rest | Measured at day 1 and day 2 | 
| SRD for Vc during exercise | SRD with 95% CI for Vc during exercise | Measured at day 1 and day 2 | 
| SRD for alveolar volume (VA) at rest | SRD with 95 % CI for VA at rest | Measured at day 1 and day 2 | 
| SRD for VA during exercise | SRD with 95 % CI for VA during exercise | Measured at day 1 and day 2 | 
| Coefficient of Variance (CV) for DLNO at rest | CV with a 95% CI at rest | Measured at day 1 and day 2 | 
| CV for DLNO during exercise | CV with a 95% CI during exercise | Measured at day 1 and day 2 | 
| CV for DLCOc at rest | CV with 95% CI for DLCOc at rest | Measured at day 1 and day 2 | 
| CV for DLCOc during exercise | CV with 95% CI for DLCOc during exercise | Measured at day 1 and day 2 | 
| CV for DM at rest | CV with 95% CI for DM at rest | Measured at day 1 and day 2 | 
| CV for DM during exercise | CV with 95% CI for DM during exercise | Measured at day 1 and day 2 | 
| CV for Vc at rest | CV with 95% CI for DM at rest | Measured at day 1 and day 2 | 
| CV for Vc during exercise | CV with 95% CI for DM during exercise | Measured at day 1 and day 2 | 
| CV for VA at rest | CV with 95% CI for VA at rest | Measured at day 1 and day 2 | 
| CV for VA during exercise | CV with 95% CI for VA during exercise | Measured at day 1 and day 2 | 
| Intraclass correlation coefficient (ICC) for DLNO at rest | ICC for DLNO with 95% CI at rest | Measured at day 1 and day 2 | 
| Intraclass correlation coefficient (ICC) for DLNO during exercise | ICC for DLNO with 95% CI during exercise | Measured at day 1 and day 2 | 
| ICC for DLCOc at rest | ICC for DLCOc with 95% CI at rest | Measured at day 1 and day 2 | 
| ICC for DLCOc during exercise | ICC for DLCOc with 95% CI during exercise | Measured at day 1 and day 2 | 
| ICC for DM at rest | ICC for DM with 95% CI at rest | Measured at day 1 and day 2 | 
| ICC for DM during exercise | ICC for DM with 95% CI during exercise | Measured at day 1 and day 2 | 
| ICC for VC at rest | ICC for VC with 95% CI at rest | Measured at day 1 and day 2 | 
| ICC for VC during exercise | ICC for VC with 95% CI during exercise | Measured at day 1 and day 2 | 
| ICC for VA at rest | ICC for VA with 95% CI at rest | Measured at day 1 and day 2 | 
| ICC for VA during exercise | ICC for VA with 95% CI during exercise | Measured at day 1 and day 2 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Diffusion capacity for nitric oxide (DLNO) at rest | DLNO at rest obtained using the combined DLCO/NO technique with a 5-sec breathhold. | Measured at day 1 and day 2 | 
| Diffusion capacity for nitric oxide (DLNO) during exercise | DLNO during exercise obtained using the combined DLCO/NO technique with a 5-sec breathhold. | Measured at day 1 and day 2 | 
| Diffusion capacity for carbon monoxide (DLCOc) at rest | DLCOc at rest obtained using the combined DLCO/NO technique with a 5-sec breathhold. | Measured at day 1 and day 2 | 
| Diffusion capacity for carbon monoxide (DLCOc) during exercise | DLCOc during exercise obtained using the combined DLCO/NO technique with a 5-sec breathhold. | Measured at day 1 and day 2 | 
| Membrane diffusing capacity (DM) at rest | DM at rest obtained using the combined DLCO/NO technique with a 5-sec breathhold. | Measured at day 1 and day 2 | 
| Membrane diffusing capacity (DM) during exercise | DM during exercise obtained using the combined DLCO/NO technique with a 5-sec breathhold. | Measured at day 1 and day 2 | 
| Pulmonary blood volume (Vc) at rest | VC at rest obtained using the combined DLCO/NO technique with a 5-sec breathhold. | Measured at day 1 and day 2 | 
| Pulmonary blood volume (Vc) during exercise | VC during exercise obtained using the combined DLCO/NO technique with a 5-sec breathhold. | Measured at day 1 and day 2 | 
| Breath hold time at rest | Breath hold time at rest obtained using the combined DLCO/NO technique with a 5-sec breathhold. | Measured at day 1 and day 2 | 
| Breath hold time during exercise | Breath hold time during exercise obtained using the combined DLCO/NO technique with a 5-sec breathhold. | Measured at day 1 and day 2 | 
| Alveolar volume (VA) at rest | VA at rest obtained using the combined DLCO/NO technique with a 5-sec breathhold. | Measured at day 1 and day 2 | 
| Alveolar volume (VA) during exercise | VA during exercise obtained using the combined DLCO/NO technique with a 5-sec breathhold. | Measured at day 1 and day 2 | 
| Bland Altman Plot - DLNO | Bland Altman plot for repeated measures for DLNO | Measured at day 1 and day 2 | 
| Bland Altman Plot - DLCOc | Bland Altman plot for repeated measures for DLCOc | Measured at day 1 and day 2 | 
| Bland Altman Plot - DM | Bland Altman plot for repeated measures for DM | Measured at day 1 and day 2 | 
| Bland Altman Plot - VC | Bland Altman plot for repeated measures for VC | Measured at day 1 and day 2 | 
| Bland Altman Plot - VA | Bland Altman plot for repeated measures for VA | Measured at day 1 and day 2 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Pulmonary diffusing capacity, Reliability, Test-retest