Effects of dexmedetomidine and propofol on lower esophageal sphincter and gastroesophageal pressure gradient in healthy volunteers.
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.
Turan
Alparslan
A
Department of Outcomes Research, The Cleveland Clinic, Cleveland, OH 44195, USA. alparslanturan@yahoo.com
Wo
John
J
Kasuya
Yusuke
Y
Govinda
Raghavendra
R
Akça
Ozan
O
Dalton
Jarrod E
JE
Sessler
Daniel I
DI
Rauch
Stefan
S
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
D006993:Hypnotics and Sedatives; D020927:Dexmedetomidine; D015742:Propofol