Related Experiment Videos
Distribution of pulmonary capillary transit times
R A Klocke1, H J Schünemann, B J Grant
1Department of Medicine, State University of New York at Buffalo, USA.
American Journal of Respiratory and Critical Care Medicine
|December 1, 1995
Summary
Pulmonary capillary transit times show a wide distribution, with most blood flow well-suited for efficient gas exchange. This suggests normal gas exchange equilibrium in the lungs under typical conditions.
Area of Science:
- Physiology
- Pulmonary Medicine
- Gas Exchange Dynamics
Background:
- Pulmonary capillary transit time is crucial for effective gas exchange.
- Understanding transit time distribution is key to pulmonary function assessment.
Purpose of the Study:
- To investigate the distribution of capillary transit times in isolated rabbit lungs.
- To determine the implications of this distribution for gas exchange equilibrium.
Main Methods:
- Isolated rabbit lungs perfused with a bicarbonate-free buffer.
- Acetylene and carbon dioxide (CO2) excretion monitored using plethysmography.
- CO2 production modulated by carbonic anhydrase inhibition.
Main Results:
- A wide distribution of capillary transit times was observed (relative dispersion, 0.45).
- Mean transit time was 1.71 seconds (± 0.53 SD).
- Only 10% of transit times were less than half the mean.
Conclusions:
- The distribution of pulmonary capillary transit times generally supports gas exchange equilibrium.
- Deviations from equilibrium may occur during strenuous exercise, high altitude, or disease states.