ISSN:
1439-6327
Keywords:
Pulmonary diffusing capacity
;
Rebreathing
;
Exercise
;
Alveolar-capillary equilibration
;
Pulmonary blood flow
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract The rebreathing technique for the measurement of the pulmonary O2 diffusing capacity, $$D_{{\text{O}}_{\text{2}} }$$ , previously developed for resting conditions [Cerretelli et al., J. appl. Physiol. 37, 526–532 (1974)] has been modified for application to exercise and simplified to one rebreathing maneuver only. The changes consist: 1) in administering in the course of a normoxic exercise a priming breath of an O2 free mixture just before the onset of rebreathing in order to achieve rapidly the appropriate starting $$P_{{\text{O}}_{\text{2}} }$$ values on the linear part of the O2 dissociation curve as required by the method; 2) in calculating mixed venous blood O2 tension by extrapolation of the alveolar to mixed venous blood $$P_{{\text{O}}_{\text{2}} }$$ equilibration curve, instead of determining it separately. While the mean $$D_{{\text{O}}_{\text{2}} }$$ value of 21 measurements on 5 subjects at rest was 30 ml·min−1·Torr−1±3 (S.E.), in 2 subjects exercising on a bicycle ergometer, $$D_{{\text{O}}_{\text{2}} }$$ was found to increase from a resting value of about 32 ml·min−1·Torr−1 to 107 ml·min−1·Torr−1 for an eightfold increase of O2 uptake. The validity and the applicability of the method are critically discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00444659
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