ABSTRACT NO: 001
Introduction: The routine use of the inert gas xenon failed because of the high costs of the substance. Recycling devices and the use of closed anaesthesia systems have renewed the interest in xenon anaesthesia. We investigated the correlation between expiratory xenon concentrations and body content of xenon in different compartments.
Methods: Seven pigs were anaesthetized with an inspiratory concentration of 70% xenon in closed-system anaesthesia. The anaesthesia time was 4 h and the washout phase was 2 h. Inert xenon131 was marked with radioactive xenon133. Organ distribution was measured with a gamma camera. Expiratory xenon concentrations were measured by mass spectrometry. Correlation coefficients were calculated for the compartments whole body, fatty tissue, lung and intestines.
Results: After the washout phase, 27.15% of the measured activity remained in the animals. Simultaneously, expiratory concentrations of 0.22% of xenon were measured. The correlation coefficient for the whole body was found to be 0.87, that for fatty tissue was 0.64, that for lung was 0.98 and that for intestines was 0.54. FIGURE
Conclusions: Measuring expiratory xenon concentrations gives a good prediction of the distribution kinetics in compartments with fast kinetics, e.g. lung. Distribution spaces with slow kinetics, e.g. fatty tissue or intestine, are less accurately included in the predictions. From the expiratory measured xenon concentration, the amount of xenon remaining in the tissues cannot be calculated exactly.
The publication of this supplement has been supported by the sponsors of the Third ISMG Meeting: Abbott, AGA, AstraZeneca, Dräger, Janssen, Medex Medical, Messer Austria, Ohmeda, Pharmacia & Upjohn, Scott Medical Products, Siemens