title: Effects of fentanyl, alfentanil, remifentanil and sufentanil on loss of consciousness and bispectral index during propofol induction of anaesthesia.
abstract: The bispectral index (BIS) and a sedation score were used to determine and compare the effect of propofol in the presence of fentanyl, alfentanil, remifentanil and sufentanil. Seventy-five non-premedicated patients were assigned randomly into five groups (15 in each) to receive fentanyl, alfentanil, remifentanil, sufentanil or placebo. Opioids were administered using a target-con-trolled infusion device, to obtain the following predicted effect-site concentrations: fentanyl, 1.5 ng ml(-1); alfentanil, 100 ng ml(-1); remifentanil, 6 ng ml(-1); and sufentanil, 0.2 ng ml(-1). After this, a target-controlled infusion of propofol (Diprifusor) was started to increase concentration gradually, to achieve predicted effect-site concentrations of 1, 2, and 4 microg ml(-1). At baseline and at each successive target effect-site concentration of propofol, the BIS, sedation score and haemodynamic variables were recorded. At the moment of loss of consciousness (LOC), the BIS and the effect-site concentration of propofol were noted. The relationship between propofol effect-site concentration and BIS was preserved with or without opioids. In the presence of an opioid, LOC occurred at a lower effect-site concentration of propofol and at a higher BIS50 (i.e. the BIS value associated with 50% probability of LOC), compared with placebo. Although clinically the hypnotic effect of propofol is enhanced by analgesic concentrations of mu-agonist opioids, the BIS does not show this increased hypnotic effect.
authors.affiliation: Division of Anaesthesiology, Geneva University Hospitals, Switzerland.
authors.forename: C
authors.initials: C
authors.lastname: Lysakowski
authors.forename: L
authors.initials: L
authors.lastname: Dumont
authors.forename: M
authors.initials: M
authors.lastname: Pellegrini
authors.forename: F
authors.initials: F
authors.lastname: Clergue
authors.forename: E
authors.initials: E
authors.lastname: Tassonyi
mesh_terms: D000328:Adult; D000368:Aged; D015760:Alfentanil / Q000494:pharmacology; D000701:Analgesics, Opioid / Q000494:pharmacology*; D018686:Anesthetics, Intravenous / Q000494:pharmacology*; D003243:Consciousness / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004569:Electroencephalography / Q000187:drug effects*; D005260:Female; D005283:Fentanyl / Q000494:pharmacology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010880:Piperidines / Q000494:pharmacology; D015742:Propofol / Q000494:pharmacology*; D000077208:Remifentanil; D017409:Sufentanil / Q000494:pharmacology
chemical_list: D000701:Analgesics, Opioid; D018686:Anesthetics, Intravenous; D010880:Piperidines; D015760:Alfentanil; D017409:Sufentanil; D000077208:Remifentanil; D005283:Fentanyl; D015742:Propofol