The effects of subanaesthetic concentrations of xenon in volunteers.
This study reports the subjective, psychomotor and physiological properties of subanaesthetic concentrations of xenon. Ten healthy male volunteers received either xenon or nitrous oxide in a randomised crossover study design. The subjects breathed either xenon (Xe) or nitrous oxide (N2O) from a closed circuit breathing system, according to a randomised, double-blind protocol. The concentration of xenon required to produce sedation, ranged between 27 and 45% (median 35%). All subjects completed the xenon protocol. Subjects were tested using the Critical Flicker Fusion test and derived electroencephalogram parameters, however, neither test was found to reliably predict sedation. The respiratory rate decreased markedly during sedation with xenon. The subjects did not experience any airway irritability (coughing, breath-holding or laryngospasm) during administration of either gas. One subject required anti-emetic treatment in the N2O group compared to none in the Xe group. Eight subjects reported that they found sedation with xenon pleasant and preferable to nitrous oxide. Xenon sedation was well tolerated and was not associated with any adverse physiological effects, however, it was reported to be subjectively dissimilar to nitrous oxide.
Bedi
A
A
The Department of Anaesthetics and Intensive Care Medicine, The Queen's University of Belfast, Northern Ireland. a.bedi@ntlworld.com
McCarroll
C
C
Murray
J M
JM
Stevenson
M A
MA
Fee
J P H
JP
D000328:Adult; D000764:Anesthesia, Closed-Circuit; D018685:Anesthetics, Inhalation / Q000008:administration & dosage* / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects; D016292:Procedural Sedation / Q000379:methods*; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004569:Electroencephalography / Q000187:drug effects; D005425:Flicker Fusion / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D009609:Nitrous Oxide / Q000494:pharmacology; D012119:Respiration / Q000187:drug effects; D012677:Sensation / Q000187:drug effects; D014978:Xenon / Q000008:administration & dosage* / Q000494:pharmacology
D018685:Anesthetics, Inhalation; D014978:Xenon; D009609:Nitrous Oxide