Time-dependent effects of prolonged hypercapnia on cerebrovascular parameters in dogs: acid-base chemistry.


Journal Article

Prolonged normoxic hypercapnia initially caused an increase in canine cerebral blood flow, as measured by the radioactive microsphere technique, accompanied by a decrease in cerebrovascular resistance. These effects persisted for 3 hours. An adaptive decrease in cerebral blood flow and increase in cerebrovascular resistance were seen when hypercapnia was maintained for an additional 3 hours. Regional variations occurred; those areas with the greatest initial hypercapnic blood flow (cortex, caudate nucleus) showed a greater rate of decay of flow over time. Cerebrospinal fluid pH, initially acidotic during hypercapnia, increased over the subsequent 5 hours from 6.99 +/- 0.02 to 7.13 +/- 0.02. This was accompanied by an increase in the cerebrospinal fluid bicarbonate ion concentration from a normocapnic baseline of 19.6 +/- 0.6 to 26.2 +/- 4 mEq/l. Total and regional cerebral blood flow were linearly related to cerebrospinal fluid pH (R2 = 0.97). Extrapolation of a full adaptive return of flow to baseline indicated a shift in the cerebrovascular sensitivity to extracellular hydrogen ion concentration during prolonged hypercapnia.

Full Text

Duke Authors

Cited Authors

  • Warner, DS; Turner, DM; Kassell, NF

Published Date

  • January 1987

Published In

Volume / Issue

  • 18 / 1

Start / End Page

  • 142 - 149

PubMed ID

  • 3810747

Pubmed Central ID

  • 3810747

International Standard Serial Number (ISSN)

  • 0039-2499

Digital Object Identifier (DOI)

  • 10.1161/01.str.18.1.142


  • eng

Conference Location

  • United States