FAILURE OF THE NITROUS OXIDE TISSUE EQUILIBRATION METHOD FOR THE DETERMINATION OF BRAIN AND MYOCARDIAL BLOOD FLOW UNDER CONTROLLED CONDITIONS

Michael A. Reid, William B. Runciman, Colin F. McLean, Laurence E. Mather

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)

Abstract

1. Two adult merino ewes were prepared with intravascular cannule for sampling aortic root blood, sagittal sinus blood and coronary sinus blood. 2. One week after preparation the animals were anaesthetized then ventilated with a gas mixture containing 10% nitrous oxide (N2O) for 60 min. Serial measurements of brain and myocardial blood flow were made using the N2O tissue equilibration method of Kety and Schmidt. 3. N2O failed to achieve matching arteriovenous blood concentration equality and saturation of the relevant tissues. Valid use of the Kety‐Schmidt method, therefore, could not be confirmed. 4. Because of the failure of the arteriovenous equilibration, serially determined brain and myocardial blood flows were found to decrease with time. 5. The use of this method in circumstances where tissue saturation with the indicator gas cannot be ascertained is arbitrary.

Original languageEnglish
Pages (from-to)229-233
Number of pages5
JournalClinical and Experimental Pharmacology and Physiology
Volume19
Issue number4
DOIs
Publication statusPublished or Issued - 1992
Externally publishedYes

Keywords

  • blood concentrations analysis
  • brain
  • cardiovascular system
  • myocardium
  • nitrous oxide
  • pharmacokinetics
  • regional blood flow
  • sheep

ASJC Scopus subject areas

  • Physiology
  • Pharmacology
  • Physiology (medical)

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