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Neurocritical Care

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01-06-2012 | Translational Research

Brain Tissue Oxygenation and Cerebral Perfusion Pressure Thresholds of Ischemia in a Standardized Pig Brain Death Model

Authors: Karlis Purins, Per Enblad, Lars Wiklund, Anders Lewén

Published in: Neurocritical Care | Issue 3/2012

Abstract

Background

Neurointensive care of traumatic brain injury (TBI) patients is currently based on intracranial pressure (ICP) and cerebral perfusion pressure (CPP) targeted protocols. Monitoring brain tissue oxygenation (B_tipO₂) is of considerable clinical interest, but the exact threshold level of ischemia has been difficult to establish due to the complexity of the clinical situation. The objective of this study was to use the Neurovent-PTO (NV) probe, and to define critical cerebral oxygenation- and CPP threshold levels of cerebral ischemia in a standardized brain death model caused by increasing the ICP in pig. Ischemia was defined by a severe increase of cerebral microdialysis (MD) lactate/pyruvate ratio (L/P ratio > 30).

Methods

B_tipO₂, L/P ratio, Glucose, Glutamate, Glycerol and CPP were recorded using NV and MD probes during gradual increase of ICP by inflation of an epidural balloon catheter with saline until brain death was achieved.

Results

Baseline level of B_tipO₂ was 22.9 ± 6.2 mmHg, the L/P ratio 17.7 ± 6.1 and CPP 73 ± 17 mmHg. B_tipO₂ and CPP decreased when intracranial volume was added. The L/P ratio increased above its ischemic levels, (>30) when CPP decreased below 30 mmHg and B_tipO₂ to <10 mmHg.

Conclusions

A severe increase of ICP leading to CPP below 30 mmHg and B_tipO₂ below 10 mmHg is associated with an increase of the L/P ratio, thus seems to be critical thresholds for cerebral ischemia under these conditions.

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Title: Brain Tissue Oxygenation and Cerebral Perfusion Pressure Thresholds of Ischemia in a Standardized Pig Brain Death Model
Authors: Karlis Purins
Per Enblad
Lars Wiklund
Anders Lewén
Publication date: 01-06-2012
Publisher: Humana Press Inc
Published in: Neurocritical Care / Issue 3/2012
Print ISSN: 1541-6933
Electronic ISSN: 1556-0961
DOI: https://doi.org/10.1007/s12028-012-9675-3

Keynote webinar | Spotlight on medication adherence

Springer Medicine

Brain Tissue Oxygenation and Cerebral Perfusion Pressure Thresholds of Ischemia in a Standardized Pig Brain Death Model

Abstract

Background

Methods

Results

Conclusions

Keynote webinar | Spotlight on medication adherence

Springer Medicine

Abstract

Background

Methods

Results

Conclusions

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