Related Experiment Videos
Single-breath pulmonary diffusing capacity. Reference values and application in connective tissue diseases and in
Scandinavian Journal of Respiratory Diseases. Supplementum
|January 1, 1976
Summary
Lung diffusing capacity (D) for carbon monoxide depends on lung volume (VA), impacting serial measurements. This study established reference values and assessed respiratory function in connective tissue diseases, finding restrictive impairment and reduced D disproportionate to lung volume changes.
Area of Science:
- Pulmonary Physiology
- Respiratory Medicine
- Rheumatology
Background:
- Diffusing capacity of the lungs (D) for carbon monoxide is a key measure of gas exchange.
- Previous studies suggest D is influenced by lung volumes, necessitating careful consideration in serial testing.
- Connective tissue diseases (CTDs) can affect respiratory function, but the specific impact on diffusing capacity requires further elucidation.
Purpose of the Study:
- To assess the repeatability and influencing factors of single-breath diffusing capacity (D) measurements.
- To establish reference values for D in healthy individuals across different age groups.
- To investigate respiratory function, particularly diffusing capacity, in patients with rheumatoid arthritis, systemic lupus erythematosus, and scleroderma.
Main Methods:
- Single-breath diffusing capacity (D) for carbon monoxide was measured using a Resparameter Mark 4.
- Reference values were determined in healthy males and females (20-69 years) using multiple linear regression.
- Respiratory function tests, including D, vital capacity, spirometry, chest X-rays, and lung biopsies, were performed on patients with CTDs.
Main Results:
- Diffusing capacity (D) and related parameters (D/VA, tau) were found to be dependent on lung volume (VA) during breath-hold.
- The method demonstrated good repeatability with a coefficient of variation of approximately 4%.
- Restrictive respiratory impairment was common in CTD patients, with D reduction often disproportionate to lung volume, particularly in scleroderma.
Conclusions:
- Lung volume during breath-hold must be accounted for in serial diffusing capacity (D) measurements.
- Established prediction equations provide a basis for evaluating D in various populations and factors like age and smoking.
- Reduced diffusing capacity, potentially due to alveolar wall thickening, is a significant finding in connective tissue diseases, warranting clinical attention.