OBSERVATIONS OF GAS BUBBLES IN PIAL VESSELS OF CATS FOLLOWING RAPID DECOMPRESSION FROM HIGH PRESSURE ATMOSPHERES

Abstract

Gas bubbles were observed directly in pial blood vessels following rapid decompression of anesthetized cats from air compressed to 75 lbs./sq. in. (gage pressure). When gas bubbles were visible in pial vessels, they always appeared first in the arteries, later in the veins. Gas bubbles were also present in other blood vessels of the body as well as in the right auricle and ventricle. Some animals died although no bubbles appeared in the pial vessels of the microscopic field under observation. Since, in all animals, the distribution of gas bubbles elsewhere in the body was the same it may be assumed that, in those instances in which bubbles were not seen, bubbles were present in arteries supplying a portion of the C. N. S. other than the field under observation. Since gas bubbles appear in pial arteries before they appear in veins, and since distribution occurs in other vessels irrespective of their appearance in pial vessels, it is concluded that pial gas bubbles are borne to their site of lodgement as gas emboli. Secondarily, as the blood flow through the region decreases, gas bubbles appear in the veins.