title: Microdialysis as a Part of Invasive Cerebral Monitoring During Porcine Septic Shock.
abstract: 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.
  
  
  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.
authors.affiliation: *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.
authors.forename: Claudia
authors.initials: C
authors.lastname: Ditz
authors.forename: Stephan
authors.initials: S
authors.lastname: Klaus
authors.forename: Ludger
authors.initials: L
authors.lastname: Bahlmann
authors.forename: Nils
authors.initials: N
authors.lastname: Onken
authors.forename: Alexander
authors.initials: A
authors.lastname: Keck
authors.forename: Jan
authors.initials: J
authors.lastname: Gliemroth
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism* / Q000503:physiopathology; D004195:Disease Models, Animal; D005260:Female; D017551:Microdialysis / Q000379:methods*; D008991:Monitoring, Physiologic / Q000379:methods*; D012772:Shock, Septic / Q000378:metabolism* / Q000503:physiopathology; D013552:Swine