Xenon suppresses the hypnotic arousal in response to surgical stimulation.

STUDY OBJECTIVE

To evaluate the suppressive effects of xenon (Xe) on hypnotic arousal at skin incision.

DESIGN

Prospective, randomized study.

SETTING

Operating rooms at a university hospital.

PATIENTS

35 ASA physical status I and II patients presenting for elective lower abdominal surgery.

INTERVENTIONS

Patients were randomly assigned to receive one of the following regimens: 1.3 minimum alveolar concentration (MAC) isoflurane, 1.3 MAC sevoflurane, 0.7 MAC Xe with 0.6 MAC sevoflurane, 1 MAC Xe with 0.3 MAC sevoflurane, or 0.7 MAC nitrous oxide (N2O) with 0.6 MAC sevoflurane (n = 7 each group).

MEASUREMENTS AND MAIN RESULTS

The bispectral index (BIS) was measured at baseline, during anesthesia, and after skin incision. BIS increased significantly at skin incision from the values noted during anesthesia in the sevoflurane and N2O groups, whereas it remained stable at incision in the other three groups (mean change in BIS: 0 +/- 9 for isoflurane, 15 +/- 8 for sevoflurane, 5 +/- 6 for 0.7 MAC Xe, 4 +/- 11 for 1 MAC Xe, and 9 +/- 5 for N2O).

CONCLUSIONS

Unlike N2O, Xe was able to suppress hypnotic arousal in response to surgical stimulation when administered with sevoflurane.