RELIABILITY OF THE SINGLE BREATH EXHALATION TECHNIQUE FOR PULMONARY DIFFUSING CAPACITY DURING EXERCISE

Pulmonary diffusing capacity of NO (Dl NO) was determined by performing single-breath experiments on six anesthetized paralyzed supine rabbits, applying inspiratory concentrations of NO (Fi NO) within a range of 10 parts per million (ppm) ≤ Fi NO ≤ 800 ppm. Starting from residual volume, the rabbit lungs were inflated by 50 ml of a NO-nitrogen-containing indicator gas mixture. Breath-holding time was set at 0.1, 1, 3, 5, and 7 s. Alveolar partial pressure of NO was determined by analyzing the end-tidal portion from expirates, with the use of respiratory mass spectrometry. In the six animals, pulmonary diffusing capacity of NO averaged Dl NO = 1.92 ± 0.21 ml ⋅ mmHg−1 ⋅ min−1(mean ± SD value). Despite extreme variations in Fi NO, we found very similar Dl NOvalues, and in three rabbits we found identical values even at such different Fi NO levels of 80 ppm or 500, 20, or 200 ppm as well as 10 or 800 ppm. There was also no dependence of Dl NO on the respective duration of the single-breath maneuvers. In addition, the time course of NO removal from alveolar space was independent of applied Fi NOlevels. These results suggest that Dl NOdeterminations are neither affected by chemical reactions of NO in alveolar gas phase as well as in lung tissue nor biased by endogenous release of NO from pulmonary tissue. It is our conclusion that the single-breath diffusing capacity of NO is able to provide a measure of alveolar-capillary gas conductance that is not influenced by the biochemical reactions of NO.

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Pulmonary Diffusing Capacity and Volumes in Healthy Adults Measured with the Single Breath Technique

Scandinavian Journal of Clinical and Laboratory Investigation ◽

10.1080/00365518209168378 ◽

1982 ◽

Vol 42 (sup159) ◽

pp. 21-34 ◽

Cited By ~ 14

Author(s):

A. A. Viljanen ◽

B. C. Viljanen ◽

P. K. Halttunen ◽

K.-E. Kreus

Keyword(s):

Healthy Adults ◽

Diffusing Capacity ◽

Pulmonary Diffusing Capacity ◽

Single Breath

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Chemiluminescent measurements of nitric oxide pulmonary diffusing capacity and alveolar production in humans

Journal of Applied Physiology ◽

10.1152/jappl.2001.91.5.1931 ◽

2001 ◽

Vol 91 (5) ◽

pp. 1931-1940 ◽

Cited By ~ 19

Author(s):

Irene B. Perillo ◽

Richard W. Hyde ◽

Albert J. Olszowka ◽

Anthony P. Pietropaoli ◽

Lauren M. Frasier ◽

...

Keyword(s):

Nitric Oxide ◽

Breath Holding ◽

No Production ◽

Diffusing Capacity ◽

Volume Changes ◽

Pulmonary Diffusing Capacity ◽

Single Breath ◽

Coefficients Of Variation ◽

Oxygen Tensions ◽

Single Constant

Measurements of nitric oxide (NO) pulmonary diffusing capacity (Dl NO) multiplied by alveolar NO partial pressure (Pa NO) provide values for alveolar NO production (V˙a NO). We evaluated applying a rapidly responding chemiluminescent NO analyzer to measure Dl NO during a single, constant exhalation (DexNO) or by rebreathing (DrbNO). With the use of an initial inspiration of 5–10 parts/million of NO with a correction for the measured NO back pressure, DexNO in nine healthy subjects equaled 125 ± 29 (SD) ml · min−1 · mmHg−1 and DrbNO equaled 122 ± 26 ml · min−1 · mmHg−1. These values were 4.7 ± 0.6 and 4.6 ± 0.6 times greater, respectively, than the subject's single-breath carbon monoxide diffusing capacity (DsbCO). Coefficients of variation were similar to previously reported breath-holding, single-breath measurements of DsbCO. Pa NOmeasured in seven of the subjects equaled 1.8 ± 0.7 mmHg × 10−6 and resulted in V˙a NO of 0.21 ± 0.06 μl/min using DexNO and 0.20 ± 0.6 μl/min with DrbNO. DexNO remained constant at end-expiratory oxygen tensions varied from 42 to 682 Torr. Decreases in lung volume resulted in falls of DexNO and DrbNO similar to the reported effect of volume changes on DsbCO. These data show that rapidly responding chemiluminescent NO analyzers provide reproducible measurements of Dl NO using single exhalations or rebreathing suitable for measuring V˙a NO.

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