The effect of xenon on isoflurane protection against experimental myocardial infarction.
OBJECTIVE
To investigate if the protective effects of xenon and isoflurane against myocardial ischemia-reperfusion damage would be additive.


METHODS
A prospective, randomized laboratory investigation.


METHODS
An animal laboratory of a university hospital.


METHODS
Thirty-six pigs (female German landrace).


METHODS
In an open-chest preparation with thiopental anesthesia, the left anterior descending artery was occluded to produce ischemia for 60 minutes. One hour previously, ischemic preconditioning, isoflurane (0.55 minimum alveolar concentration [MAC]) alone, or isoflurane together with xenon (0.55 MAC each) were started in the respective groups. A fourth (control) group received no protective intervention. Myocardial ischemia was followed by 2 hours of reperfusion.


RESULTS
Hearts were excised and stained (Evans Blue/TTC) to measure infarct size as related to the area at risk. Myocardial infarct size was reduced (means +/- standard deviation) from 64% +/- 9% of the area at risk in the control group to 19% +/- 12% with ischemic preconditioning to 46% +/- 12% with isoflurane and to 39% +/- 13% with isoflurane and xenon. All intervention groups were significantly different from the control (p < 0.05), and both anesthetic groups were significantly different from ischemic preconditioning (p < 0.05).


CONCLUSIONS
Combined isoflurane/xenon anesthesia reduced infarct size but not more than isoflurane alone. Ischemic preconditioning was more effective than the anesthetics.
Department of Anesthesiology, University Clinic, Aachen, Germany. jan.baumert@googlemail.com
Jan H
JH
Baumert
Marc
M
Hein
Christina
C
Gerets
Thomas
T
Baltus
Klaus E
KE
Hecker
Rolf
R
Rossaint
D000818:Animals; D004195:Disease Models, Animal; D004359:Drug Therapy, Combination; D005260:Female; D019157:Ischemic Preconditioning, Myocardial / Q000379:methods; D007530:Isoflurane / Q000008:administration & dosage* / Q000627:therapeutic use; D009203:Myocardial Infarction / Q000473:pathology / Q000517:prevention & control*; D011446:Prospective Studies; D013552:Swine; D014978:Xenon / Q000008:administration & dosage*
D014978:Xenon; D007530:Isoflurane