title: Cerebral and Peripheral Metabolism to Predict Successful Reperfusion After Cardiac Arrest in Rats: A Microdialysis Study.
abstract: BACKGROUND
  In clinical practice, monitoring of the efficacy of resuscitation can be challenging. The prediction of cerebral and overall outcome in particular is an unmet medical need. Microdialysis is a minimally invasive technique for the continuous determination of metabolic parameters in vivo. Using this technique, we set out to establish a model allowing for concomitant determination of cerebral and peripheral metabolism in a cardiac arrest setting in rodents.
  
  
  METHODS
  Microdialysis settings were optimized in vitro and then used in male Sprague-Dawley rats. Probes were implanted into the CA1 region of the right hippocampus and the right femoral vein. With a time interval of 8 min, glucose, lactate, pyruvate, and glutamate levels were determined during baseline conditions, untreated ventricular fibrillation cardiac arrest, cardiopulmonary resuscitation (CPR), reperfusion, and death.
  
  
  RESULTS
  In 16 rodents, restoration of spontaneous circulation was achieved in seven animals. Characteristic metabolic changes were evident during cardiac arrest and reperfusion with both probes. Ischemic patterns in peripheral compartments were delayed and more variable compared to the changes in cerebral metabolism highlighting the importance of cerebral metabolic monitoring. Microdialysis allowed distinguishing between survivors and non-survivors 8 min after termination of CPR. Cerebral glutamate showed a trend toward higher levels in non-survivors during CPR.
  
  
  CONCLUSIONS
  We established a new rodent model for research in hypoxic ischemic encephalopathy. This setting allows to investigate the impact of resuscitation methods on cerebral and peripheral metabolism simultaneously. The present model may be used to evaluate different resuscitation strategies in order to optimize brain survival in future studies.
authors.affiliation: Department of Neurosurgery, Medical University of Vienna, Vienna, Austria.
authors.forename: A
authors.initials: A
authors.lastname: Hosmann
authors.affiliation: Department of Emergency Medicine, Medical University of Vienna, Vienna, Austria.
authors.forename: A
authors.initials: A
authors.lastname: Schober
authors.affiliation: Department of Neurosurgery, Medical University of Vienna, Vienna, Austria.
authors.forename: A
authors.initials: A
authors.lastname: Gruber
authors.affiliation: Department of Emergency Medicine, Medical University of Vienna, Vienna, Austria.
authors.forename: F
authors.initials: F
authors.lastname: Sterz
authors.affiliation: Department of Emergency Medicine, Medical University of Vienna, Vienna, Austria.
authors.forename: C
authors.initials: C
authors.lastname: Testori
authors.affiliation: Department of Emergency Medicine, Medical University of Vienna, Vienna, Austria.
authors.forename: A
authors.initials: A
authors.lastname: Warenits
authors.affiliation: Department of Emergency Medicine, Medical University of Vienna, Vienna, Austria.
authors.forename: W
authors.initials: W
authors.lastname: Weihs
authors.affiliation: University of Veterinary Medicine, Vienna, Austria.
authors.forename: S
authors.initials: S
authors.lastname: Högler
authors.affiliation: Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria.
authors.forename: T
authors.initials: T
authors.lastname: Scherer
authors.affiliation: Department of Emergency Medicine, Medical University of Vienna, Vienna, Austria.
authors.forename: A
authors.initials: A
authors.lastname: Janata
authors.affiliation: Department of Emergency Medicine, Medical University of Vienna, Vienna, Austria.
authors.forename: A
authors.initials: A
authors.lastname: Laggner
authors.affiliation: Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria. markus.zeitlinger@meduniwien.ac.at.
authors.forename: Markus
authors.initials: M
authors.lastname: Zeitlinger
mesh_terms: D000818:Animals; D056547:CA1 Region, Hippocampal / Q000378:metabolism*; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D004195:Disease Models, Animal; D005268:Femoral Vein / Q000378:metabolism*; D006323:Heart Arrest / Q000378:metabolism*; D008297:Male; D017551:Microdialysis / Q000379:methods*; D064926:Neurophysiological Monitoring / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley; D015424:Reperfusion / Q000379:methods*
keywords: Animal model; Cardiac arrest; Cerebral metabolism; Ischemia; Microdialysis; Neuromonitoring; Reperfusion; Resuscitation