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61st Annual Meeting of the German Society of Neurosurgery (DGNC) as part of the Neurowoche 2010
Joint Meeting with the Brazilian Society of Neurosurgery on the 20 September 2010

German Society of Neurosurgery (DGNC)

21 - 25 September 2010, Mannheim

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Comparison of two different modes of measuring cerebral tissue oxygenation – challenges and interpretation

Meeting Abstract

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  • Julius Dengler - Klinik und Poliklinik für Neurochirurgie, Charité – Universitätsmedizin Berlin, Germany
  • Christin Frenzel - Klinik und Poliklinik für Neurochirurgie, Charité – Universitätsmedizin Berlin, Germany
  • Peter Vajkoczy - Klinik und Poliklinik für Neurochirurgie, Charité – Universitätsmedizin Berlin, Germany
  • Stefan Wolf - Klinik und Poliklinik für Neurochirurgie, Charité – Universitätsmedizin Berlin, Germany
  • Peter Horn - Klinik und Poliklinik für Neurochirurgie, Charité – Universitätsmedizin Berlin, Germany

Deutsche Gesellschaft für Neurochirurgie. 61. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC) im Rahmen der Neurowoche 2010. Mannheim, 21.-25.09.2010. Düsseldorf: German Medical Science GMS Publishing House; 2010. DocP1864

doi: 10.3205/10dgnc335, urn:nbn:de:0183-10dgnc3355

Published: September 16, 2010

© 2010 Dengler et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en). You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.

Outline

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Objective: Multimodal monitoring of brain function in comatose patients after severe brain trauma and subarachnoid hemorrhage is gaining importance in clinical routine. Cerebral tissue oxygenation (ptiO2) is most frequently monitored using a Licox system (Integra Neuroscience, Germany) but recently a new probe was introduced by a different manufacturer (Raumedic, Germany). Currently there are no prospective data on how both probes compare during interventional modification of inspirational oxygen fraction (FiO2). In this prospective study we compare in vivo measurements of ptiO2 by both probes in the setting of varying FiO2.

Methods: 10 patients with an indication for intraparenchymal ptiO2-measurement during intensive care treatment were included. Each patient received a Licox and a Raumedic probe side by side into the same cerebrovascular region. PtiO2 was recorded continuously. Once a steady baseline value was reached FiO2 was increased by 20 percent for 10 minutes. Evaluation was performed at baseline and 10 minutes after FiO2 increase with regression and Bland Altman analyses.

Results: Mean measurement time per patient was 7.5 days (±2.6). A total of 60 phases of ptiO2 measurements were recorded during interventional FiO2 modification. Mean difference in ptiO2 was significant with a baseline value of 6.4 mmHg (±12.4) compared to 3.6 mmHg (±18.1) after intervention. Licox values were predominantly lower than the ones measured with the Raumedic probe. A significant difference was observed in mean reaction times to the increase in FiO2 with 140 seconds (±32) for Licox compared to 350 seconds for Raumedic. Reaction times to the decrease of FiO2 differed even more with 180 seconds for Licox compared to 700 (±55) seconds for Raumedic.

Conclusions: This study shows that Licox and Raumedic ptiO2 probes measure different values in routine monitoring. This is also true for phases of dynamic changes in FiO2 during which the Licox probe responds significantly faster to changes in blood oxygenation. These results are especially relevant since both probes were located in the same cerebrovascular region. Our data therefore do not support the view that both probes equivalently measure ptiO2 and can be used interchangeably.