gms | German Medical Science

58. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e. V. (DGNC)

Deutsche Gesellschaft für Neurochirurgie (DGNC) e. V.

26. bis 29.04.2007, Leipzig

Relationship between cerebrovascular pressure autoregulation and the cerebral oxygen regulatory system after head injury

Beziehung zwischen zerebrovaskulärer Druckautoregulation und dem System der zerebralen Sauerstoffregulierung nach Schädel-Hirn-Trauma

Meeting Abstract

  • corresponding author M. Jaeger - Klinik und Poliklinik für Neurochirurgie, Universitätsklinikum Leipzig
  • C. Nagel - Klinik und Poliklinik für Neurochirurgie, Universitätsklinikum Leipzig
  • M. Schuhmann - Klinik und Poliklinik für Neurochirurgie, Universitätsklinikum Leipzig
  • M. Söhle - Klinik und Poliklinik für Anästhesie und Intensivmedizin, Universitätsklinikum Bonn
  • J. Meixensberger - Klinik und Poliklinik für Neurochirurgie, Universitätsklinikum Leipzig

Deutsche Gesellschaft für Neurochirurgie. 58. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC). Leipzig, 26.-29.04.2007. Düsseldorf: German Medical Science GMS Publishing House; 2007. DocFR.06.03

Die elektronische Version dieses Artikels ist vollständig und ist verfügbar unter: http://www.egms.de/de/meetings/dgnc2007/07dgnc098.shtml

Veröffentlicht: 11. April 2007

© 2007 Jaeger et al.
Dieser Artikel ist ein Open Access-Artikel und steht unter den Creative Commons Lizenzbedingungen (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.de). Er darf vervielf&aauml;ltigt, verbreitet und &oauml;ffentlich zug&aauml;nglich gemacht werden, vorausgesetzt dass Autor und Quelle genannt werden.


Gliederung

Text

Objective: The human brain possesses several regulatory systems. Besides pressure autoregulation of cerebral blood flow, mechanisms to control cerebral oxygen content are described. It is poorly understood, however, how these systems are related to each other and what the effects of traumatic brain injury are? Thus, the aim of this study was to investigate the relationship between cerebrovascular pressure autoregulation and the cerebral oxygen regulatory system.

Methods: Following severe head injury in ten patients, continuous monitoring of mean arterial pressure (MAP), intracranial pressure (ICP), and partial pressure of brain tissue oxygen (PtiO2) were performed. Brain tissue oxygen response (TOR, response of PtiO2 to changes in arterial oxygen) was investigated by increasing the fraction of inspired oxygen to 1.0 for 15 minutes and calculated according to van Santbrink et al. (van Santbrink et al., Acta Neurochir (Wien) 2003) In nine patients, two oxygen challenges were applied, whereas in one patient only one oxygen challenge was performed. Cerebrovascular pressure autoregulation was assessed using the index of cerebrovascular pressure reactivity (PRx), calculated as the moving correlation coefficient between MAP and ICP.

Results: Arterial oxygen increased from 108±6 mmHg to 495±64 mmHg during ventilation with 100% oxygen. Simultaneously, PtiO2 increased from 26±7 mmHg to 77±27 mmHg, resulting in a mean TOR of 0.49±0.20. Arterial carbon dioxide, MAP, and ICP remained stable during the oxygen challenge. The mean PRx during a 12-hour-period prior to ventilation with 100% oxygen was 0.09±0.18. The relationship between pooled data of TOR and PRx was highly significant (Spearman r=0.77, p=0.009).

Conclusions: The results of our study propose a close relationship between cerebrovascular pressure autoregulation and the ability of the brain to control its parenchymal extracellular oxygen content. This is of interest, since it suggests that both systems are equally disturbed after head injury. Furthermore, it might be hypothesised that the ability of the brain to autoregulate blood flow may be controlled, at least in part, by oxygen sensing mechanisms.