gms | German Medical Science

62. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC)
Joint Meeting mit der Polnischen Gesellschaft für Neurochirurgen (PNCH)

Deutsche Gesellschaft für Neurochirurgie (DGNC) e. V.

07. - 11. Mai 2011, Hamburg

Comparison of a modified cerebral pressure reactivity index with conventional PRx: Improved prognostic value and similar CPPopt estimation

Meeting Abstract

  • E. Santos - Department of Neurosurgery, University of Heidelberg, Heidelberg, Germany
  • J. Diedler - Department of Neurology, University of Heidelberg, Heidelberg, Germany
  • M. Sykora - Department of Neurology, University of Heidelberg, Heidelberg, Germany
  • B. Orakcioglu - Department of Neurosurgery, University of Heidelberg, Heidelberg, Germany
  • M. Kentar - Department of Neurosurgery, University of Heidelberg, Heidelberg, Germany
  • M. Czosnyka - Department of Clinical Neurosciences, Neurosurgical Unit, University of Cambridge, Addenbrooke's Hospital, Cambridge
  • A. Unterberg - Department of Neurosurgery, University of Heidelberg, Heidelberg, Germany
  • O.W. Sakowitz - Department of Neurosurgery, University of Heidelberg, Heidelberg, Germany

Deutsche Gesellschaft für Neurochirurgie. Polnische Gesellschaft für Neurochirurgen. 62. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), Joint Meeting mit der Polnischen Gesellschaft für Neurochirurgen (PNCH). Hamburg, 07.-11.05.2011. Düsseldorf: German Medical Science GMS Publishing House; 2011. DocMO.06.06

DOI: 10.3205/11dgnc034, URN: urn:nbn:de:0183-11dgnc0340

Veröffentlicht: 28. April 2011

© 2011 Santos 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 vervielfältigt, verbreitet und öffentlich zugänglich gemacht werden, vorausgesetzt dass Autor und Quelle genannt werden.


Gliederung

Text

Objective: Cerebral Pressure reactivity index (PRx) correlates with outcome in patients with intracerebral haemorrhage (ICH) and has been used to define an autoregulation-oriented “optimal cerebral perfusion pressure” (CPPopt). PRx is based on the assumption that with intact vasoreactivity, an increase in MAP will trigger cerebral vasoconstriction, reflected by a decrease in ICP. PRx thus is calculated as moving correlation of 10 sec averages of MAP and ICP, using a 5 minutes moving time window, in order to reflect changes within a time frame of 20 sec to 2 minutes. However, due to this calculation method, PRx has a poor signal-to-noise ratio. Here, we introduce an alternative calculation method (L-PRx) based on one-minute averages of the ICP and MAP raw data, comparing it to the standard PRx and assessing its predictive value for outcome.

Methods: A total of 548.5 hours of artefact free data (sampling frequency 1 Hz) of 18 patients suffering from non-traumatic ICH were included in the analysis. We compared the standard PRx with a different calculation method where rapid fluctuations of MAP and ICP are cancelled (waves of >0.01Hz) by calculating a mean per minute for MAP and ICP. L-PRx was calculated using minute averages of both MAP and ICP in 20 minutes moving correlation windows. CPPopt, defined as CPP value with lowest PRx values, was calculated based on standard PRx and on L-PRx.

Results: The averaged PRx values of the total monitoring period for each patient correlated with the L-PRx (P=0.846, p<0.001). CPPopt based on standard PRx was identified in 8 patients. In contrast, based on L-PRx, a CPPopt value could be found in 12 patients. CPPopt values of both methods correlated highly (P=0.980, p<0.001). L-PRx had a better correlation (0.667, p=0.002) with NIHSS at discharge than PRx (0.563, p=0.015).

Conclusions: In our patient series L-PRx better correlated with outcome than standard PRx. CPPopt from both methods correlated highly, but CPPopt could be identified in more patients using L-PRx. Slower changes of MAP and ICP (in the range of 1-20 min) can be used for autoregulation assessment and contain important prognostic information.

*The two first authors contributed equally.