Regional inhomogeneity of alveolar air and R.Q. differences in the lungs of the normal dog

¹ Department of Physiology, Hahnemann Medical College, Philadelphia, Pennsylvania

Regional inhomogeneity of alveolar air was studied by simultaneous sampling through catheters in primary or secondary bronchi, at the end of normal expiration in dogs under sodium pentobarbital anesthesia. With dogs lying on the back, the right lung usually had the lower Pco₂, higher Po₂ and higher R. P(t) < .001 for each difference. In the side-lying position the ‘down’ lung usually had the higher Po₂ and R unless the catheters were placed so deep as to differentially obstruct the airway in that lung.