title: The effect of nitrous oxide inhalation on the hypotensive response to propofol: a randomized controlled trial.
abstract: OBJECTIVE
  Decrease in arterial blood pressure is a prominent adverse reaction during propofol (Disoprivan; AstraZeneca K.K., Osaka, Japan) sedation. The purpose of this prospective randomized study was to explore the effects of nitrous oxide (N2O) on the hypotensive response during propofol sedation.
  
  
  METHODS
  Twenty-six healthy volunteers received intravenous sedation with propofol alone (group P, n=13) or a combined technique using 20% N2O and propofol (group N+P, n=13). Propofol was administered by a target-controlled infusion system to attain and maintain a plasma propofol concentration of 1.5μg/mL. Hemodynamic and autonomic parameters were measured.
  
  
  RESULTS
  Mean arterial pressure decreased in both groups, the hypotensive response in group N+P being significantly smaller than in group P. Reduction in the low-frequency power of systolic blood pressure variability, indicative of sympathetic nervous activity, was also smaller in group N+P than in group P.
  
  
  CONCLUSIONS
  Addition of N2O to propofol sedation can attenuate the hypotensive effect of propofol.
authors.affiliation: Clinical Fellow, Department of Dental Anesthesiology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan.
authors.forename: Chizuko
authors.initials: C
authors.lastname: Yokoe
authors.affiliation: Assistant Professor, Department of Dental Anesthesiology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hanamoto
authors.affiliation: Assistant Professor, Department of Dental Anesthesiology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan.
authors.forename: Aiji
authors.initials: A
authors.lastname: Boku
authors.affiliation: Associate Professor, Department of Dental Anesthesiology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan.
authors.forename: Mitsutaka
authors.initials: M
authors.lastname: Sugimura
authors.affiliation: Associate Professor, Department of Dental Anesthesiology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan.
authors.forename: Yoshinari
authors.initials: Y
authors.lastname: Morimoto
authors.affiliation: Assistant Professor, Department of Dental Anesthesiology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan.
authors.forename: Chiho
authors.initials: C
authors.lastname: Kudo
authors.affiliation: Professor, Department of Dental Anesthesiology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan. Electronic address: hanamoto@dent.osaka-u.ac.jp.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Niwa
mesh_terms: D000280:Administration, Inhalation; D000328:Adult; D018685:Anesthetics, Inhalation / Q000008:administration & dosage*; D018686:Anesthetics, Intravenous / Q000008:administration & dosage; D001794:Blood Pressure / Q000187:drug effects*; D005260:Female; D064368:Healthy Volunteers; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007022:Hypotension / Q000139:chemically induced* / Q000517:prevention & control*; D007564:Japan; D008297:Male; D008991:Monitoring, Physiologic; D009609:Nitrous Oxide / Q000008:administration & dosage*; D015742:Propofol / Q000008:administration & dosage
chemical_list: D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D009609:Nitrous Oxide; D015742:Propofol