title: Brain metabolism during cardiopulmonary resuscitation assessed with microdialysis.
abstract: OBJECTIVE
  Microdialysis is an established tool to analyse tissue biochemistry, but the value of this technique to monitor cardiopulmonary resuscitation (CPR) effects on cerebral metabolism is unknown. The purpose of this study was to assess the effects of active-compression-decompression (ACD) CPR in combination with an inspiratory threshold valve (ITV) (=experimental CPR) vs. standard CPR on cerebral metabolism measured with microdialysis.
  
  
  METHODS
  Fourteen domestic pigs were surfaced-cooled to a body core temperature of 26 degrees C and ventricular fibrillation was induced, followed by 10 min of untreated cardiac arrest; and subsequently, standard (n=7) CPR vs. experimental (n=7) CPR. After 8 min of CPR, all animals received 0.4 U/kg vasopressin IV, and CPR was maintained for an additional 10 min in each group; defibrillation was attempted after a total of 28 min of cardiac arrest, including 18 min of CPR.
  
  
  RESULTS
  In the standard CPR group, microdialysis measurements showed a 13-fold increase of the lactate-pyruvate ratio from 7.2+/-1.3 to 95.5+/-15.4 until the end of CPR (P<0.01), followed by a further increase up to 138+/-32 during the postresuscitation period. The experimental group developed a sixfold increase of the lactate-pyruvate ratio from 7.1+/-2.0 to 51.1+/-8.7 (P<0.05), and a continuous decrease after vasopressin. In the standard resuscitated group, but not during experimental CPR, a significant increase of cerebral glucose levels from 0.6+/-0.1 to 2.6+/-0.5 mM was measured (P<0.01).
  
  
  CONCLUSIONS
  Using the technique of microdialysis we were able to measure changes of brain biochemistry during and after the very special situation of hypothermic cardiopulmonary arrest. Experimental CPR improved the lactate-pyruvate ratio, and glucose metabolism.
authors: Department of Anesthesiology, Medical University of Luebeck, Ratzeburger Allee 160, D-23538 Lübeck, Germany. lbahlm@aol.com
authors: Ludger
authors: L
authors: Bahlmann
authors: Stefan
authors: S
authors: Klaus
authors: Wolfgang
authors: W
authors: Baumeier
authors: Peter
authors: P
authors: Schmucker
authors: Claus
authors: C
authors: Raedler
authors: Christian A
authors: CA
authors: Schmittinger
authors: Volker
authors: V
authors: Wenzel
authors: Wolfgang
authors: W
authors: Voelckel
authors: Karl H
authors: KH
authors: Lindner
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001921:Brain / Q000378:metabolism*; D002545:Brain Ischemia / Q000503:physiopathology; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D002560:Cerebrovascular Circulation / Q000502:physiology; D004195:Disease Models, Animal; D005260:Female; D006323:Heart Arrest / Q000401:mortality / Q000628:therapy*; D008297:Male; D017551:Microdialysis / Q000379:methods*; D011336:Probability; D011897:Random Allocation; D018570:Risk Assessment; D018709:Statistics, Nonparametric; D015996:Survival Rate; D034421:Sus scrofa; D014667:Vasopressins / Q000494:pharmacology*
chemical_list: D014667:Vasopressins