Clinical Assessments of Pulmonary Diffusing Capacity
Conditions
Brief summary
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 involves a very short breath-hold time (≤5 seconds), and it may be repeated up to 12 times without affecting measurements, and it is thus ideal for assessing acute changes in pulmonary diffusing capacity and its components during various physiological manoeuvres. The aim of the present study is to compare the test-retest reliability of pulmonary diffusing capacity measurements during postural changes (sitting vs. supine) vs. rest-to-exercise. DLCO/NO will either be measured in the sitting position during rest vs. exercise or in the sitting and supine posture, and this will be repeated within 1-7 days in 20 healthy individuals that will be randomised to one of the two interventions. Statistically,the test-retest relaibility of sitting-to-supine vs. rest-to-exercise changes in DLCO/NO will be compared by parametric methods.
Interventions
DIAGNOSTIC_TESTRest-to-exercise
Pulmonary diffusing capacity is assessed at rest and during exercise (70% of VO2max on a bicycle ergometer)
DIAGNOSTIC_TESTSitting-to-supine
Pulmonary diffusing capacity is assessed in the sitting and supine position
Sponsors
Rigshospitalet, Denmark
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
DIAGNOSTIC
Masking
NONE
Intervention model description
Randomised study
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
• Regular exercise (1-3 timer per week)
Exclusion criteria
* Any known medical condition that requires regular medication or any known lung condition * Smoking * Symptoms of disease within 2 weeks prior to the study * Abnormal lung function test * Pregnancy
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Between intervention DLNO/DLCO-ratio repeatability coefficient | 1 week | Test-retest reliability coefficient of rest-to-exercise and supine-to-prone DLNO/DLCO-ratio |
| Between intervention DLCO repeatability coefficient | 1 week | Test-retest repeatability coefficient of rest-to-exercise and supine-to-prone DLCO |
| Between intervention DLNO repeatability coefficient | 1 week | Test-retest repeatability coefficient of rest-to-exercise and supine-to-prone DLNO |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Between intervention DM repeatability coefficient | 1 week | Test-retest repeatability coefficient of rest-to-exercise and supine-to-prone DM |
| Between intervention Vc repeatability coefficient | 1 week | Test-retest repeatability coefficient of rest-to-exercise and supine-to-prone Vc |
Other
| Measure | Time frame | Description |
|---|---|---|
| DM SEM | 1 week | Between-day SEM of DM from rest-to-exercise and supine-to-prone |
| Vc SEM | 1 week | Between-day SEM of Vc from rest-to-exercise and supine-to-prone |
| DLNO/DLCO-ratio CV | 1 week | Between-day CV of DLNO/DLCO from rest-to-exercise and supine-to-prone |
| DLCO CV | 1 week | Between-day CV of DLCO from rest-to-exercise and supine-to-prone |
| DLNO CV | 1 week | Between-day CV of DLNO from rest-to-exercise and supine-to-prone |
| DM CV | 1 week | Between-day CV of DM from rest-to-exercise and supine-to-prone |
| Vc CV | 1 week | Between-day CV of Vc from rest-to-exercise and supine-to-prone |
| DM MDC | 1 week | Between-day MDC of DM from rest-to-exercise and supine-to-prone |
| Vc MDC | 1 week | Between-day Vc of DM from rest-to-exercise and supine-to-prone |
| DLNO/DLCO-ratio ICC | 1 week | Between-day ICC of DLNO/DLCO from rest-to-exercise and supine-to-prone |
| DM ICC | 1 week | Between-day ICC of DM from rest-to-exercise and supine-to-prone |
| DLNO ICC | 1 week | Between-day ICC of DLNO from rest-to-exercise and supine-to-prone |
| Between day DLNO/DLCO-ratio repeatability coefficient | 1 week | Between-day repeatability coefficient of DLNO/DLCO at rest in both groups combined |
| Between day DLCO repeatability coefficient | 1 week | Between-day repeatability coefficient of DLCO at rest in both groups combined |
| Between day DLNO repeatability coefficient | 1 week | Between-day repeatability coefficient of DLNO at rest in both groups combined |
| Between day DM repeatability coefficient | 1 week | Between-day repeatability coefficient of DM at rest in both groups combined |
| Between day Vc repeatability coefficient | 1 week | Between-day repeatability coefficient of Vc at rest in both groups combined |
| DLNO/DLCO-ratio MDC | 1 week | Between-day MDC of DLNO/DLCO from rest-to-exercise and supine-to-prone |
| DLCO MDC | 1 week | Between-day MDC of DLCO from rest-to-exercise and supine-to-prone |
| DLNO MDC | 1 week | Between-day MDC of DLNO from rest-to-exercise and supine-to-prone |
| DLCO ICC | 1 week | Between-day ICC of DLCO from rest-to-exercise and supine-to-prone |
| Vc ICC | 1 week | Between-day ICC of Vc from rest-to-exercise and supine-to-prone |
| DLNO/DLCO-ratio SEM | 1 week | Between-day SEM of DLNO/DLCO from rest-to-exercise and supine-to-prone |
| DLCO SEM | 1 week | Between-day SEM of DLCO from rest-to-exercise and supine-to-prone |
| DLNO SEM | 1 week | Between-day SEM of DLNO from rest-to-exercise and supine-to-prone |
Countries
Denmark
Outcome results
None listed