Comparative effects of xenon and nitrous oxide on diaphragmatic contractility in dogs.
BACKGROUND
Xenon at two different concentrations (30%, 60%) has no effect on diaphragmatic contractility. This study was undertaken to compare the effects of xenon and nitrous oxide (N2O), a commonly used and well-established gas anesthetic, on diaphragmatic contractility in dogs.


METHODS
Twenty-one pentobarbitone-anesthetized dogs were randomly divided into three groups of seven each: group 1 received xenon 30% (0.25 MAC) in oxygen; group 2 received N2O 47% (0.25 MAC) in oxygen; and group 3 received N2O 60% (0.32 MAC) in oxygen. Diaphragmatic contractility was assessed by transdiaphragmatic pressure (Pdi) at low- (20-Hz) and high-frequency (100-Hz) stimulation, after maintaining 60 min of stable condition. The integrated electrical activity of diaphragm (Edi) to each stimulus was measured.


RESULTS
With an inhalation of xenon 30%, N2O 47%, or N2O 60%, Pdi and Edi at both stimuli did not change. No difference in Pdi or Edi was observed among the groups.


CONCLUSIONS
When used at clinical concentration, xenon or N2O does not affect contractility and electrical activity of the diaphragm in dogs.
Hoshi
T
T
Department of Anesthesiology, University of Tsukuba Institute of Clinical Medicine, Ibaraki, Japan.
Fujii
Y
Y
Toyooka
H
H
D000704:Analysis of Variance; D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D000818:Animals; D003964:Diaphragm / Q000187:drug effects* / Q000502:physiology; D004285:Dogs; D009119:Muscle Contraction / Q000187:drug effects*; D009609:Nitrous Oxide / Q000494:pharmacology*; D014978:Xenon / Q000494:pharmacology*
D018685:Anesthetics, Inhalation; D014978:Xenon; D009609:Nitrous Oxide