title: Practical aspects of the use of target controlled infusion with remifentanil in neurosurgical patients: predicted cerebral concentrations at intubation, incision and extubation.
abstract: Remifentanil has important side effects and it is not easy to know what remifentanil concentrations should be used during different endpoints of anaesthesia. We analyzed the remifentanil predicted effect-site concentrations (RemiCe) at different events during neurosurgical procedures and assessed if the concentrations used were clinically adequate. BIS and haemodynamic parameters were collected every 5 seconds. Predicted cerebral concentration of propofol (PropCe) and RemiCe were analyzed immediately prior to respective stimulus, and 30, 60 and 90 seconds after. RemiCe were 2.2 +/- 0.3, 6 +/- 2.6 and 2.2 +/- 0.9 ng ml(-1) at intubation, incision and extubation, respectively. PropCe observed in the same periods were 5 +/- 1, 2.6 +/- 0.9 and 1 +/- 0.3 microg ml(-1), also respectively. The remifentanil concentrations used in our patients were lower than reported concentrations, while being clinically adequate to minimize the haemodynamic response to stimulation.
authors.affiliation: Departamento de Matemática Aplicada, Faculdade de Ciências da Universidade do Porto, Portugal. davidor@utad.pt
authors.forename: D A
authors.initials: DA
authors.lastname: Ferreira
authors.forename: C S
authors.initials: CS
authors.lastname: Nunes
authors.forename: L
authors.initials: L
authors.lastname: Antunes
authors.forename: F
authors.initials: F
authors.lastname: Lobo
authors.forename: P
authors.initials: P
authors.lastname: Amorim
mesh_terms: D000328:Adult; D000368:Aged; D000768:Anesthesia, General; D018686:Anesthetics, Intravenous / Q000008:administration & dosage* / Q000493:pharmacokinetics; D001794:Blood Pressure / Q000187:drug effects; D001921:Brain / Q000378:metabolism*; D016503:Drug Delivery Systems; D004569:Electroencephalography / Q000187:drug effects; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007262:Infusions, Intravenous; D007442:Intubation, Intratracheal; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures; D010880:Piperidines / Q000008:administration & dosage* / Q000493:pharmacokinetics; D015742:Propofol; D000077208:Remifentanil
chemical_list: D018686:Anesthetics, Intravenous; D010880:Piperidines; D000077208:Remifentanil; D015742:Propofol