title: Use of xenon as a sedative for patients receiving critical care.
abstract: OBJECTIVE
  Many sedative regimens are used in the intensive care setting, but none are wholly without adverse effect. Xenon is a noble gas with sedative and analgesic properties. It has been used successfully as a general anesthetic and has many desirable properties, not least of which is a minimal effect on the myocardium. In theory, xenon may provide sedation without adverse effect for certain groups of critically ill patients. The objective of this study was to assess the feasibility of using xenon as an intensive care sedative.
  
  
  METHODS
  Double-blind, randomized study.
  
  
  METHODS
  Tertiary-level intensive care unit.
  
  
  METHODS
  Twenty-one patients admitted to an intensive care unit following elective thoracic surgery.
  
  
  METHODS
  A standard intensive care sedation regimen (intravenous propofol at 0-5 mg.kg-1.hr-1 and alfentanil 30 microg.kg-1.hr-1) was compared with a xenon sedation regimen delivered using a novel bellows-in-bottle delivery system. MEASUREMENTS AND MAIN RESULTS Each sedative regimen was continued for 8 hrs. The hemodynamic effects, additional analgesic requirements, recovery from sedation, and effect on hematological and biochemical variables were compared for the two sedation regimens. All patients were successfully sedated during the xenon regimen. The mean +/- SD end-tidal xenon concentration required to provide sedation throughout the duration of the study was 28 +/- 9.0% (range, 9-62%). Arterial systolic, diastolic, and mean pressures showed a greater tendency for negative gradients in patients receiving the propofol regimen (p <.05, p <.1, and p <.01, respectively). Recovery following xenon was significantly faster than from the standard sedation regimen (p <.0001). Hematological and biochemical laboratory markers were within normal clinical limits in both groups.
  
  
  CONCLUSIONS
  Xenon provided satisfactory sedation in our group of patients. It was well tolerated with minimal hemodynamic effect. Recovery from this agent is extremely rapid. We have demonstrated the feasibility of using xenon within the critical care setting, without adverse effect.
authors.affiliation: Royal Group of Hospitals, Belfast, Northern Ireland.
authors.forename: Amit
authors.initials: A
authors.lastname: Bedi
authors.forename: James M
authors.initials: JM
authors.lastname: Murray
authors.forename: John
authors.initials: J
authors.lastname: Dingley
authors.forename: Michael A
authors.initials: MA
authors.lastname: Stevenson
authors.forename: J P Howard
authors.initials: JP
authors.lastname: Fee
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015760:Alfentanil; D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D018686:Anesthetics, Intravenous; D016292:Procedural Sedation; D003422:Critical Care; D004311:Double-Blind Method; D005240:Feasibility Studies; D005260:Female; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D011182:Postoperative Care; D015742:Propofol; D014978:Xenon / Q000494:pharmacology*
chemical_list: D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D015760:Alfentanil; D014978:Xenon; D015742:Propofol