Accession Number : AD0289287

Title :   EFFECTS OF CHANGES IN BLOOD PC02 ON BRAIN OXYGENATION AT 147 MM HG AMBIENT PRESSURE (39,000 FEET)

Corporate Author : PENNSYLVANIA UNIV PHILADELPHIA

Personal Author(s) : PIERCE,E.C. JR. ; LAMBERTSEN,C.J.

Report Date : JUN 1962

Pagination or Media Count : 1

Abstract : Hyperventila ion during the breathing of 100% oxygen elevates the oxygen tension of alveolar gas by the same amount that it lower it CO2 ten ion. Since the development of art rial hypocapnia causes cerebral vasoconstriction, brai oxygenation is drastically decr sed even while arterial oxygenation i improved by the hyperventilation. ministration of 30% CO2 with oxygen at an ambient pressure equivalent to tha at 39,00 feet al itude pr v ed alkalemia and, i spi of yp rv ntil tio restore central oxygenation to a level at least equivalent to that found when pure o ygen w s br ath at r e altitude. Th respiratory mi ute volum duri g administration of CO2 with O2 was greater than when O2 alone was breathed t the re uc a bi pr ur S INCE N ITH R AR RIAL O YG ION NOR CENTRAL CO2 tension values differed in these two experimental situations, the respiratory stimulatio may represent t u n i tive de o tra io i a of a r spir tory effect of carbo dioxide which is mediated solely by the chemoreceptors exposed to arteri l blood nd which acts in the abse ce of a ch g i ir c c r l i ul tio by CO2. ( UTHOR)

Descriptors :   *OXYGEN, *POISONING, ACID BASE EQUILIBRIUM, BLOOD CIRCULATION, BRAIN, CHEMORECEPTORS, METABOLISM DISORDERS, OXYGEN CONSUMPTION, PH FACTOR, PRESSURE

Distribution Statement : APPROVED FOR PUBLIC RELEASE