title: Aspiration induced by remifentanil: a double-blind, randomized, crossover study in healthy volunteers.
abstract: BACKGROUND
  Remifentanil is widely used for monitored anesthesia care in spontaneously breathing patients. However, the authors' previous studies have shown that remifentanil induces subjective swallowing difficulties, which may increase the risk of aspiration.
  
  
  METHODS
  Twenty-five healthy volunteers participated in a double-blind, randomized, crossover trial at the University Hospital in Örebro, Örebro, Sweden. The volunteers were studied on two different occasions during which they received either remifentanil with an effect-site target concentration of 3 ng/ml or saline over 1 h. A radionuclide tracer was infused simultaneously into the nasopharynx at a rate of 0.1 ml/min. Aspiration was determined by lung scans, and subjective swallowing difficulties and grip strength were evaluated. The primary outcome was the difference in occurrence of aspiration between remifentanil and placebo treatments. The secondary outcomes were differences in swallowing difficulty and grip strength and the association between aspiration and swallowing difficulty.
  
  
  RESULTS
  During remifentanil and placebo infusion, 48 and 12% of the volunteers aspirated, respectively, difference: 36% (95% CI, 10 to 62%). A similar significant difference was found for swallowing difficulties but not for the association between aspiration and swallowing. No difference was found in grip strength between the two treatments.
  
  
  CONCLUSIONS
  Remifentanil infusion at concentrations used in monitored anesthesia care increases the incidence of aspiration. However, the subjective swallowing difficulty induced by remifentanil is not indicative of the aspiration risk.
authors.affiliation: From the Department of Anaesthesiology and Intensive Care, Örebro University Hospital, Örebro, Sweden; School of Health and Medical Sciences; Örebro University, Örebro, Sweden (J.S., M.W.); Department of Anaesthesiology and Intensive Care, Örebro University Hospital, Örebro, Sweden; School of Health and Medical Sciences; Örebro University, Örebro, Sweden; Centre for Health Care Sciences, Örebro University Hospital, Örebro, Sweden (R.A.); Clinical Epidemiology and Biostatistic Unit, Örebro University Hospital, Örebro, Sweden (A.M.); and Department of Radiology, Örebro University Hospital, Örebro, Sweden (H.G.).
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: Håkan
authors.initials: H
authors.lastname: Geijer
authors.forename: Magnus
authors.initials: M
authors.lastname: Wattwil
mesh_terms: D000293:Adolescent; D000328:Adult; D018686:Anesthetics, Intravenous / Q000009:adverse effects*; D018592:Cross-Over Studies; D003627:Data Interpretation, Statistical; D003679:Deglutition / Q000187:drug effects; D004311:Double-Blind Method; D005260:Female; D018737:Hand Strength; D006801:Humans; D007262:Infusions, Intravenous; D008168:Lung / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000187:drug effects; D010880:Piperidines / Q000009:adverse effects*; D011015:Pneumonia, Aspiration / Q000139:chemically induced* / Q000000981:diagnostic imaging; D011859:Radiography; D000077208:Remifentanil; D015656:Respiratory Mechanics / Q000187:drug effects; D018570:Risk Assessment; D055815:Young Adult
chemical_list: D018686:Anesthetics, Intravenous; D010880:Piperidines; D000077208:Remifentanil