Effect on xenon on diaphragmatic contractility in dogs

Purpose: This study was undertaken to examine the effect of xenon on diaphr agmatic contractility in pentobarbitone- anesthetized, mechanically ventila ted dogs. Methods: Twenty-one dogs were randomly allocated to three groups (n=7 of ea ch): Group I received oxygen 100%; Group II received xenon 30% in oxygen; G roup III received xenon 60% in oxygen. Diaphragmatic contractility was asse ssed by measuring transdiaphragmatic pressure (Pdi) generated during supram aximal stimulation of phrenic nerves at the neck at low-frequency (20-Hz) a nd high-frequency (100-Hz) stimulation, after maintaining 60 min of stable condition. Results: With inhalation of xenon at two different concentration (30% and 6 0%), no changes were observed in Pdi at either concentration. There was no difference in Pdi among the three groups. Conclusion: Increasing the concentration of xenon to 60% has no effect on d iaphragmatic contractility in dogs. This suggests that xenon may be used sa fely as an anesthetic with respect to respiratory muscle function.