title: Effects of remifentanil on the esophagogastric junction and swallowing.
abstract: BACKGROUND
  A recent study demonstrated that reflux is associated with impaired pressure augmentation in the esophagogastric junction (EGJ), caused by diaphragmal contractions during inspiration. It is unknown whether this augmentation is influenced by opioids. Swallowing difficulties can be a poorly recognised side effect of remifentanil. Here, we investigated whether remifentanil influences inspiratory EGJ augmentation and evaluated subjective swallowing difficulties induced by remifentanil. We also used the peripheral opioid receptor antagonist methylnaltrexone to evaluate whether these effects are centrally or peripherally mediated.
  
  
  METHODS
  Ten healthy volunteers participated in a double-blind, randomised, cross-over trial at the University Hospital in Örebro, Sweden. They were studied on two different occasions, during which they were randomly assigned to receive either methylnaltrexone 0.15 mg/kg or saline subcutaneously 30 min before the target-controlled infusion of remifentanil of 3 ng/mL. EGJ pressures were measured by high-resolution manometry. Swallowing difficulties were assessed when volunteers performed dry swallows. The outcomes were the differences in EGJ pressures at baseline and during remifentanil infusion and with methylnaltrexone vs. placebo. Differences in swallowing difficulties before and during remifentanil, and with methylnaltrexone vs. placebo were also recorded.
  
  
  RESULTS
  Remifentanil decreased the inspiratory EGJ augmentation and induced swallowing difficulties. No statistically significant differences between methylnaltrexone and placebo occasions were found.
  
  
  CONCLUSIONS
  Remifentanil may increase risk for gastroesophageal reflux by decreasing the inspiratory EGJ augmentation. The clinical significance of remifentanil-induced swallowing difficulties is to be studied further. Given the limited sample size, it cannot be concluded whether these effects are centrally or peripherally mediated.
authors.affiliation: Department of Anesthesiology and Intensive Care, Örebro University Hospital, Örebro, Sweden. johanna.savilampi@orebroll.se
authors.forename: Johanna
authors.initials: J
authors.lastname: Savilampi
authors.forename: Rebecca
authors.initials: R
authors.lastname: Ahlstrand
authors.forename: Anders
authors.initials: A
authors.lastname: Magnuson
authors.forename: Magnus
authors.initials: M
authors.lastname: Wattwil
mesh_terms: D000328:Adult; D018686:Anesthetics, Intravenous / Q000494:pharmacology*; D018592:Cross-Over Studies; D003627:Data Interpretation, Statistical; D003679:Deglutition / Q000187:drug effects*; D004311:Double-Blind Method; D004943:Esophagogastric Junction / Q000187:drug effects*; D005260:Female; D006801:Humans; D008297:Male; D008365:Manometry; D009271:Naltrexone / Q000031:analogs & derivatives / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D010880:Piperidines / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology; D017450:Receptors, Opioid, mu / Q000037:antagonists & inhibitors; D000077208:Remifentanil; D013270:Stomach / Q000187:drug effects / Q000502:physiology; D055815:Young Adult
chemical_list: D018686:Anesthetics, Intravenous; D009292:Narcotic Antagonists; D010880:Piperidines; D000644:Quaternary Ammonium Compounds; D017450:Receptors, Opioid, mu; C032257:methylnaltrexone; D009271:Naltrexone; D000077208:Remifentanil