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Updated: Apr 1, 2026

Standardized Hemorrhagic Shock Induction Guided by Cerebral Oximetry and Extended Hemodynamic Monitoring in Pigs
Published on: May 21, 2019
Microdialysis as a Part of Invasive Cerebral Monitoring During Porcine Septic Shock
Claudia Ditz1, Stephan Klaus, Ludger Bahlmann
1*Department of Neurosurgery, University of Lübeck, Lübeck †Department of Anesthesiology, Herz-Jesu-Krankenhaus Hiltrup GmbH, Münster ‡Department of Anesthesiology, Sankt Ansgar-Krankenhaus, Höxter §Department of Pediatrics, Klinikum Bremen-Mitte, Bremen ∥Department of Obstetrics and Gynecology, Klinikum Osnabrück, Osnabrück, Germany.
Background:
Metabolic changes in critically ill patients with endotoxin-induced septic shock are measured primarily by techniques that afford organ-specific metabolic monitoring based on interstitial fluid samples. The present study was designed to evaluate the role of cerebral microdialysis (MD) as a part of invasive neuromonitoring during endotoxemia in a porcine model.
Materials And Methods:
Continuous endotoxin infusion was administered to 7 female pigs and, in addition to hemodynamic monitoring and blood chemistry, interstitial lactate, pyruvate, glucose and glycerol concentrations in muscle, liver, and cerebral tissue were measured via in vivo MD for an observation period of 180 minutes.
Results:
The cerebral concentrations of lactate and glycerol showed no significant increases, whereas the hepatic and muscular levels rose dramatically under endotoxemia. However, the lactate/pyruvate ratio and especially the lactate/glucose ratio showed a profound and significant increase in brain tissue as well. Cerebral perfusion pressure decreased from 77 to 50 mm Hg without reaching pathologic values.
Conclusions:
Although our results confirm the special protection of the brain during endotoxemia compared with other organs, early metabolic changes become evident by increasing lactate/pyruvate ratio and lactate/glucose ratio. MD appears to be a suitable additional technique in invasive neuromonitoring for obtaining early information about metabolic deterioration in the brain during septic shock.

