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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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Correlation of pressure-, oxygen- and flow- related indices of cerebrovascular reactivity in a porcine model of intracerebral hemorrhage

Meeting Abstract

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  • Edgar Santos - University Hospital Heidelberg, Department of Neurosurgery, Heidelberg, Germany
  • Berk Orakcioglu - University Hospital Heidelberg, Department of Neurosurgery, Heidelberg, Germany
  • Modar Kentar - University Hospital Heidelberg, Department of Neurosurgery, Heidelberg, Germany
  • Yoichi Uozumiv - University Hospital Heidelberg, Department of Neurosurgery, Heidelberg, Germany
  • Michael Schöll - Department of Medical Informatics, University of Heidelberg, Germany
  • Andreas Unterberg - University Hospital Heidelberg, Department of Neurosurgery, Heidelberg, Germany
  • Oliver W. Sakowitz - University Hospital Heidelberg, Department of Neurosurgery, Heidelberg, 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. DocP1867

doi: 10.3205/10dgnc338, urn:nbn:de:0183-10dgnc3380

Published: September 16, 2010

© 2010 Santos 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: Impaired cerebrovascular reactivity (CR) has been associated with adverse outcome in patients with intracerebral hemorrhage (ICH). Microdialysis is a method to assess important aspects of brain metabolism. Changes in metabolite concentrations have been associated with primary and secondary brain damage. The aim of this study was to determine a pressure- , and oxygen-, and a flow- related index of CR in a porcine model of ICH and to correlate each of these indices with cerebral metabolite concentrations.

Methods: Continuous advanced multimodal monitoring including microdialysis, cerebral blood flow and PbrO2 probes were placed 1cm in front of the coronal suture in the grey white matter junction. Following a period of 1 hour of monitoring, an autologous arterial ICH with defined volumes (2 to 3 ml) was induced using a catheter tubing system connected to the femoral artery. Based on the data collected, pressure-, oxygen-, and flow-related autoregulation indices (PRx, ORx and FRx) were simultaneously calculated and hourly correlated with microdialysis metabolites including Glucose, Lactate, Pyruvate and Glutamate.

Results: All animals (n=17) were monitored on average 12 continuous hours. FRx highly correlated with ORx (0.96, P=<0.001) but values of both FRx and ORx >0.2 did not correlate with any microdialysis metabolite. PRx >0.2 highly correlated (0.65, P<0.001) with Lactate/Pyruvate ratio, PRx >0.3 correlated (0.67, P=0.01) with Glutamate. Individual monitoring demonstrated critical hypoxic episodes where PRx were high (>0.4). Simultaneous increases of Lactate and Glutamate, and decrease in Glucose were observed. These reversed after augmenting cerebral perfusion pressure and oxygenation. Nevertheless, there were occasional episodes where microdialysis revealed evidence of hypoxia that was not associated with PRx >0.2.

Conclusions: We found evidence for impaired cerebral vasomotor activity in a porcine model of ICH. The findings suggest that at least PRx abnormalities could be associated with microdialysis alterations during hypoxic events.