gms | German Medical Science

60th Annual Meeting of the German Society of Neurosurgery (DGNC)
Joint Meeting with the Benelux countries and Bulgaria

German Society of Neurosurgery (DGNC)

24 - 27 May 2009, Münster

Introduction of a new intracerebral PbrO2-probe in an experimental swine model

Meeting Abstract

  • B. Orakcioglu - Neurochirurgische Klinik, Ruprecht-Karls-Universität Heidelberg
  • K. Kiening - Neurochirurgische Klinik, Ruprecht-Karls-Universität Heidelberg
  • O. Sakwowitz - Neurochirurgische Klinik, Ruprecht-Karls-Universität Heidelberg
  • C. Beynon - Neurochirurgische Klinik, Ruprecht-Karls-Universität Heidelberg
  • J. Neumann - Neurochirurgische Klinik, Ruprecht-Karls-Universität Heidelberg
  • A. Unterberg - Neurochirurgische Klinik, Ruprecht-Karls-Universität Heidelberg

Deutsche Gesellschaft für Neurochirurgie. 60. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), Joint Meeting mit den Benelux-Ländern und Bulgarien. Münster, 24.-27.05.2009. Düsseldorf: German Medical Science GMS Publishing House; 2009. DocMI.08-08

DOI: 10.3205/09dgnc228, URN: urn:nbn:de:0183-09dgnc2286

Published: May 20, 2009

© 2009 Orakcioglu et al.
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Outline

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Objective: Neuromonitoring in neurocritically ill patients using continuous PbrO2-measurement has been widely accepted. However, only one reliable PbrO2-neuromonitoring system in clinical use has been sufficiently studied so far. New PbrO2-technologies are now available on the market. Our goal is to test a new PbrO2-probe (TO, Raumedics®) vs. the established Licox-technology (IntegraNeurosciences®).

Methods: In nine male swine two different (TO vs. Licox) PbrO2-catheters were implanted into the subcortical area. Contralaterally, a parenchymal ICP-probe was inserted. All relevant physiological parameters were continuously recorded. We performed physiological maneuvers such as FiO2-challenges, medically induced hypo- and hypertension, TRIS-buffer application and hyper- and hypoventilation. Post mortem the parenchymal catheter locations were macroscopically controlled. Bland-Altman plots were generated to statistically compare both technologies.

Results: The Bland-Altman analysis revealed a good comparability of both technologies under baseline conditions (meandiff = 2,09 mm Hg). Mean values during FiO2-challenges (FiO2 = 100%) showed significantly different profiles. The TO-probe reached up to 1.5 fold higher PbrO2 values than the Licox-probe. This may be explained by an “O2-consumptive” effect of the Licox technology. During hypoventilation (FiO2 = 5%), the TO-probe indicated the hypoxic level of 8.5 mm Hg two minutes before Licox which may play an important role in critically ill patients. All other maneuvers showed similar responses in both technologies. The TO-probe is easy to handle, and does not need a specific storage or calibration procedure before implantation. It is a solid probe that is not very sensitive to breakage. It can be inserted using a multilumen bolt-kit as the caliber is small (2 mm). In addition, the brain temperature is recorded simultaneously.

Conclusions: We present a new PbrO2-technology that was experimentally compared to the “gold standard” Licox. We provide data that the new PbrO2 technology (TO) will reliably measure PbrO2 under physiological conditions as compared to Licox. However, the TO-probe is more sensitive to O2-changes which may have a positive effect on patient outcome, especially with critically low PbrO2-values. Further studies, i.e. using cerebral microdialysis, are needed to evaluate whether both technologies have the same numeric hypoxic level.