GASEOUS EXCHANGES IN THE PULMONARY ALVEOLI
Abstract
An analysis of the air expelled from the lungs during explosive decompression indicated a marked increase in the percentage of CO2 and O2 present. Experiments with a mass spectrometer (MS) indicated that the equilibrium in the lung alveoli was completely established by the time the last of the expanding air had escaped from the lungs. when the composition of the air was suddenly changed, the time required for the establishment of the new equilibrium depended upon the rapidity with which the lungs were ventilated with air of different composition. This usually required about 10 complete respiratory cycles. Continuous analysis of the expired air indicated that the PCO2 (the partial pressure of CO2) rose more rapidly than the pO2 fell. A study of similar variations in pulmonary venous blood in dogs under artificial respiration indicated that the CO2 content was higher just before the beginning of deflation than it was immediately following inflation. An MS determination of respiratory dead space was attempted in which human subjects (1) breathed normally while at rest, (2) hyperventilated voluntarily, and (3) exercised violently on the bicyle ergometer. The MS method gave slightly lower values than the conventional method because the MS measures the volume of air which is unmixed with alveolar air.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 15, 1953
- Accession Number
- AD0014084
Entities
People
- Fred A. Hitchcock
Organizations
- Ohio State University