Related Experiment Videos
Real-time gas analysis improves the measurement of single-breath diffusing capacity
1Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710.
The American Review of Respiratory Disease
|October 1, 1992
Summary
A new rapid analyzer improves single-breath diffusing capacity of the lung for carbon monoxide (DLCOsb) measurements. This method accurately determines washout volume (Vwash) and uses smaller sample volumes (Vsamp), enhancing DLCOsb analysis.
Area of Science:
- Pulmonary Physiology
- Respiratory Medicine
- Medical Instrumentation
Background:
- Traditional single-breath diffusing capacity of the lung for carbon monoxide (DLCOsb) measurements rely on slow analyzers and assumed washout volumes (Vwash).
- These limitations necessitate large sample volumes (Vsamp) for gas analysis, potentially impacting accuracy.
- Recent advancements include rapid analyzers that continuously measure CO and an inert tracer gas (CH4).
Purpose of the Study:
- To compare the American Thoracic Society (ATS) guideline method with a novel visual inspection (VIS) method for DLCOsb analysis.
- To evaluate the accuracy of Vwash and Vsamp determination using a rapid analyzer.
- To assess DLCOsb measurement feasibility in patients with small vital capacities (VC).
Main Methods:
- Utilized a rapid analyzer to continuously measure CO and CH4 in 135 DLCOsb measurements from 70 patients.
- Compared the standard ATS guideline method (fixed Vwash and Vsamp) with the VIS method (visually determined Vwash and fixed Vsamp).
- Analyzed DLCOsb attainment in patients with VC < 1.2 L and compared Vwash and Vsamp between the two methods in other patients.
Main Results:
- DLCOsb was successfully measured in four patients with VC < 1.2 L using a small Vsamp (< 500 ml).
- In 50% of the remaining patients, the VIS-Vwash was less than or equal to the ATS-Vwash, indicating adequate clearance with ATS criteria.
- In the other 50% of patients, VIS-Vwash exceeded ATS-Vwash, suggesting ATS criteria might not have cleared phases I and II adequately.
Conclusions:
- A rapid analyzer allows for accurate Vwash determination and utilization of smaller Vsamp for DLCOsb measurements.
- The VIS method offers a potentially more accurate approach to Vwash determination compared to fixed ATS criteria.
- This technology enhances the feasibility and accuracy of DLCOsb testing, particularly in patients with limited lung volumes.