title: Effects of dexmedetomidine and propofol on lower esophageal sphincter and gastroesophageal pressure gradient in healthy volunteers.
abstract: BACKGROUND
  Many anesthetics reduce lower esophageal sphincter pressure (LESP). Reduced pressure and consequent reduction in the gastroesophageal pressure gradient (GEPG) thus promotes gastroesophageal reflux and may contribute to aspiration pneumonia and associated morbidity. Therefore, the authors compared LESP and GEPG during dexmedetomidine and propofol sedation.
  
  
  METHODS
  Using a randomized, double-blind, crossover design, 11 healthy volunteers were sedated on 2 separate days. Baseline LESP and GEPG were recorded each day. Subsequently, on each day volunteers received three 40-min-long sedative infusions of increasing doses of 0.6, 1.2, and 2.4 ng/ml dexmedetomidine or 1, 2, and 4 microg/ml propofol. LESP and GEPG were recorded during inhalation and expiration at 20 and 40 min after starting each infusion phase, and these measurements were averaged. Results are presented as mean (95% confidence interval).
  
  
  RESULTS
  Two subjects did not return for the dexmedetomidine study day, and the dexmedetomidine results were unusable in another; propofol results in these volunteers were nonetheless retained for analysis. There were no significant differences in LESP and GEPG as a function of drug. However, there was a small but significant 7.4 (-1.6 to -13.2) mmHg (approximately 25%) dose-dependent decrease in LESP over the range of targeted low to high blood levels of each drug.
  
  
  CONCLUSIONS
  Both dexmedetomidine and propofol have similar effects on LESP and GEPG. Although both of the drugs cause some decrease in LESP at high concentrations, it is unlikely that this effect would promote gastroesophageal reflux during sedation.
authors.affiliation: Department of Outcomes Research, The Cleveland Clinic, Cleveland, OH 44195, USA. alparslanturan@yahoo.com
authors.forename: Alparslan
authors.initials: A
authors.lastname: Turan
authors.forename: John
authors.initials: J
authors.lastname: Wo
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Kasuya
authors.forename: Raghavendra
authors.initials: R
authors.lastname: Govinda
authors.forename: Ozan
authors.initials: O
authors.lastname: Akça
authors.forename: Jarrod E
authors.initials: JE
authors.lastname: Dalton
authors.forename: Daniel I
authors.initials: DI
authors.lastname: Sessler
authors.forename: Stefan
authors.initials: S
authors.lastname: Rauch
mesh_terms: D000293:Adolescent; D000328:Adult; D018592:Cross-Over Studies; D020927:Dexmedetomidine / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D049630:Esophageal Sphincter, Lower / Q000187:drug effects*; D004947:Esophagus / Q000502:physiology*; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives / Q000494:pharmacology*; D008297:Male; D008365:Manometry; D011312:Pressure; D015742:Propofol / Q000494:pharmacology*; D013270:Stomach / Q000502:physiology*; D055815:Young Adult
chemical_list: D006993:Hypnotics and Sedatives; D020927:Dexmedetomidine; D015742:Propofol