The contribution of arterial blood gases in cerebral blood flow regulation and fuel utilization in man at high altitude.

Published

Journal Article

The effects of partial acclimatization to high altitude (HA; 5,050 m) on cerebral metabolism and cerebrovascular function have not been characterized. We hypothesized (1) increased cerebrovascular reactivity (CVR) at HA; and (2) that CO2 would affect cerebral metabolism more than hypoxia. PaO2 and PaCO2 were manipulated at sea level (SL) to simulate HA exposure, and at HA, SL blood gases were simulated; CVR was assessed at both altitudes. Arterial-jugular venous differences were measured to calculate cerebral metabolic rates and cerebral blood flow (CBF). We observed that (1) partial acclimatization yields a steeper CO2-H(+) relation in both arterial and jugular venous blood; yet (2) CVR did not change, despite (3) mean arterial pressure (MAP)-CO2 reactivity being doubled at HA, thus indicating effective cerebral autoregulation. (4) At SL hypoxia increased CBF, and restoration of oxygen at HA reduced CBF, but neither had any effect on cerebral metabolism. Acclimatization resets the cerebrovasculature to chronic hypocapnia.

Full Text

Duke Authors

Cited Authors

  • Willie, CK; MacLeod, DB; Smith, KJ; Lewis, NC; Foster, GE; Ikeda, K; Hoiland, RL; Ainslie, PN

Published Date

  • May 2015

Published In

Volume / Issue

  • 35 / 5

Start / End Page

  • 873 - 881

PubMed ID

  • 25690474

Pubmed Central ID

  • 25690474

Electronic International Standard Serial Number (EISSN)

  • 1559-7016

Digital Object Identifier (DOI)

  • 10.1038/jcbfm.2015.4

Language

  • eng

Conference Location

  • United States