Brain metabolism during cardiopulmonary resuscitation assessed with microdialysis.
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.
Bahlmann
Ludger
L
Department of Anesthesiology, Medical University of Luebeck, Ratzeburger Allee 160, D-23538 Lübeck, Germany. lbahlm@aol.com
Klaus
Stefan
S
Baumeier
Wolfgang
W
Schmucker
Peter
P
Raedler
Claus
C
Schmittinger
Christian A
CA
Wenzel
Volker
V
Voelckel
Wolfgang
W
Lindner
Karl H
KH
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*
D014667:Vasopressins