CIMIT Summer Education Series 2009: Frontiers of Inhalation Technologies in Biomedical Sciences and Clinical Medicine

7.21.2009 Role of Inhalation Technologies for Organ Protection and Patient Sedation in Critical Care: Xenon Anesthesia – What Else? SPEAKER: Philippe Richebé, MD, PhD: University of Washington MODERATOR: Moderator: Augustine Choi, MD: BWH, CIMIT

Forum Summary

The ideal anesthetic, a standard to which xenon can be compared, must be potent and must be of low solubility, and it must also be safe and easy for anesthesiologists to use.  Xenon does not possess all the attributes of the ideal anesthetic, but it has many advantages.

Xenon is an NMDA receptor antagonist, and because of its low solubility, it is an on-off drug.  Even if a patient has been under xenon anesthesia for a long time, it usually takes the patient only approximately five minutes to regain orientation.  The minimum alveolar concentration for xenon anesthesia is approximately sixty percent, and although this number is higher than would be ideal, xenon anesthesia can still be delivered with approximately forty percent oxygen. 

A number of studies have shown that xenon anesthesia is as good as or better than other options.  Xenon has been shown to maintain hemodynamic stability more effectively than some other anesthetics, such as isoflurane.  Xenon seems to have no effect on myocardial contractility, and it is better than propofol at maintaining a patient’s blood pressure.  In animals, xenon has been shown to reduce the size of myocardial infarcts if used during reperfusion, and early results indicate that it may also have neuroprotective properties.  Perhaps the strongest evidence in favor of xenon anesthesia is the fact the patients who received xenon anesthesia spent less post-operative time in intensive care units than other patients.

Although more research needs to be done, it seems that xenon has many, albeit not all, of the attributes of the ideal anesthetic. It is safe and does not produce atmospheric pollution.  It provides good hemodynamic stability, and its low solubility means that it can be used as an on-off drug.  Xenon’s disadvantages include the fact that its minimum alveolar concentration is relatively high and the fact that it is expensive and rare.   

---

Post a Comment