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Cerebral PtO2, Acute Hypoxia, and Volatile Anesthetics in the Rat Brain

  • Huagang Hou
  • Oleg Y. Grinberg
  • Stalina A. Grinberg
  • Nadeem Khan
  • Jeff F. Dunn
  • Harold M. Swartz
Conference paper
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 566)

Abstract

We describe our results on the effect in rats of two commonly used, volatile anesthetics on cerebral tissue PO2 (PtO2) and other physiological parameters at FiO2 levels ranging from 0.35 to 0.1. The study was performed in 12 rats that had lithium phthalocyanine (LiPc) crystals implanted in the left cerebral cortex. FiO2 was maintained at 0.35 during surgical manipulation and baseline EPR measurements, after which time, each animal was exposed to varying levels of FiO2 (0.26, 0.21, 0.15, and 0.10) for 30 minutes at each level. No significant difference in PtO2 was observed between the isoflurane and halothane groups at any FiO2 level, and the cerebral arterial PO2 (PaO2) also was similar for both groups. However, the cerebral PtO2 under both isoflurane and halothane anesthesia was lower during hypoxia (FiO2 ≤ 0.15) than under normoxia (FiO2=0.21) and there was a significant difference in mean arterial blood pressure (MABP) between isoflurane and halothane groups under both mild and severe hypoxia. The pH and cerebral arterial PCO2 (PaCO2) were similar for the halothane and isoflurane groups during normoxia (FiO2=0.21) and mild hypoxia (FiO2=0,15), but following severe hypoxia (FiO2=0.10), both parameters were lower in the halothane anesthetized animals. These results confirm that cerebral PO2 cannot be inferred directly from measurements of other parameters, indicating that methodology incorporating continuous direct measurement of brain oxygen will lead to a better understanding of cerebral oxygenation under anesthesia and hypoxia.

Keywords

Cerebral Blood Flow Mean Arterial Blood Pressure Volatile Anesthetic Cerebral Oxygenation Severe Hypoxia 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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6. References

  1. 1.
    E. L. Rolett, A. Azzawi, K. J. Liu, M. N. Yongbi, H. M. Swartz, and J. F. Dunn, Critical oxygen tension in rat brain: a combined 31P-NMR and EPR oximetry study, Am. J. Physiol. Regulatory Integrative Comp. Physiol. 279(1), R9–R16 (2000).Google Scholar
  2. 2.
    H. Lei, O. Y. Grinberg, C. I. Nwaigwe, H. G. Hou, H. Williams, H. M. Swartz, and J. F. Dunn, The effects of ketamine/xylazine anesthesia on cerebral blood flow and oxygenation observed using nuclear magnetic resonance perfusion imaging and electron paramagnetic resonance oximetry, Brain Res. 913(2), 174–179 (2001).PubMedCrossRefGoogle Scholar
  3. 3.
    W. E. Hoffman, D.J. Miletich, and R.F. Albrecht, The effects of midazolam on cerebral blood flow and oxygen consumption and its interaction with nitrous oxide, Anesth. Analg. 65(7), 729–733 (1986).PubMedGoogle Scholar
  4. 4.
    R. A. Berkowitz, W. E. Hoffman, F. Cunningham, and T. McDonald, Changes in cerebral blood flow velocity in children during sevoflurane and halothane anesthesia, J. Neurosurg. Anesthesiol. 8(3), 194–198 (1996).PubMedGoogle Scholar
  5. 5.
    H. G. Hou, O. Y. Grinberg, S. Taie, S. Leichtweis, M. Miyake, S. Grinberg, H. Xie, M. Csete, and H. M. Swartz, Electron paramagnetic resonance assessment of brain tissue oxygen tension in anesthetized rats, Anesth. Analg. 96(5), 1467–1472 (2003).PubMedCrossRefGoogle Scholar
  6. 6.
    K. J. Liu, P. Gast, M. Moussavi, S. W. Norby, N. Vahidi, T. Walczak, M. Wu, and H. M. Swartz, Lithium phthalocyanine: A probe for electron paramagnetic resonance oximetry in viable biological systems. Proc. Natl. Acad. Sci. USA 90(12), 5438–5442 (1993).PubMedCrossRefGoogle Scholar
  7. 7.
    H. M. Swartz, and R. B. Clarkson, The measurement of oxygen in vivo using EPR techniques, Phys. Med. Biol. 43(7), 1957–1975 (1998).PubMedCrossRefGoogle Scholar
  8. 8.
    M. J. Nilges, T. Walczak, and H. M. Swartz, 1 GHz in vivo ESR spectrometer operating with a surface probe, Phys. Med. 5, 195–201 (1989).Google Scholar
  9. 9.
    A. I. Mass, W. Fleckenstein, D. A. De Jong, and H. van Santbrink, Monitoring cerebral oxygenation: experimental studies and preliminary clinical results of continuous monitoring of cerebrospinal fluid and brain tissue oxygen tension, Acta Neurochir. Suppl. (Wien) 59, 50–57 (1993).Google Scholar
  10. 10.
    W. A. van den Brink, I. K. Haitsma, C. J. Avezaat, A. B. Houtsmuller, J. M. Kros, and A. I. Maas, Brain parenchyma/pO2 catheter interface: a histopathological study in the rat, J. Neurotrauma 15(10), 813–824 (1998).PubMedCrossRefGoogle Scholar
  11. 11.
    B. A. McKinley, W. P. Morris, C. L. Parmley, and B. D. Butler, Brain parenchyma PO2, PCO2, and pH during and after hypoxic, ischemic brain insult in dogs, Crit. Care Med. 24(11), 1858–1868 (1996).PubMedCrossRefGoogle Scholar
  12. 12.
    N. Dahlgren, Local cerebral blood flow in spontaneously breathing rats subjected to graded isobaric hypoxia, Acta Anaesthesiol. Scand. 34(6), 463–467 (1990).PubMedCrossRefGoogle Scholar
  13. 13.
    P. Lebrun-Grandie, J. C. Baron, F. Soussaline, C. Loch’h, J. Sastre, and M. G. Bousser, Coupling between regional blood flow and oxygen utilization in the normal human brain. A study with positron tomography and oxygen 15, Arch. Neural. 40(4), 230–236 (1983).Google Scholar
  14. 14.
    M. J. Hernandez, R. W. Brennan, and G. S. Bowman, Cerebral blood flow autoregulation in the rat, Stroke 9(2), 150–155 (1978).PubMedGoogle Scholar
  15. 15.
    J. B. Madsen, G. E. Cold, E. S. Hansen, and B. Bardrum, The effect of isoflurane on cerebral blood flow and metabolism in humans during craniotomy for small supratentorial cerebral tumors, Anesthesiol. 66(3), 332–336 (1987).Google Scholar
  16. 16.
    M. M. Todd, and J. C. Drummond, A comparison of the cerebrovascular and metabolic effects of halothane and isoflurane in the cat, Anesthesiol. 60(4), 276–282 (1984).CrossRefGoogle Scholar
  17. 17.
    D. G. Nehls, M. M. Todd, R. F. Spetzler, J. C. Drummond, R. A. Thompson, and P. C. Johnson, A comparison of the cerebral protective effects of isoflurane and barbiturates during temporary focal ischemia in primates, Anesthesiol. 66(4), 453–464 (1987).Google Scholar

Copyright information

© Springer Science+Business Media, Inc. 2005

Authors and Affiliations

  • Huagang Hou
  • Oleg Y. Grinberg
  • Stalina A. Grinberg
  • Nadeem Khan
  • Jeff F. Dunn
  • Harold M. Swartz

There are no affiliations available

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