title: No clinical evidence of acute opioid tolerance after remifentanil-based anaesthesia.
abstract: We have prospectively assessed whether remifentanil-based anaesthesia is associated with clinically relevant acute opioid tolerance, expressed as greater postoperative pain scores or morphine consumption. Sixty patients undergoing elective gynaecological, non-laparoscopic, surgery were randomly assigned to receive remifentanil (group R, n=30) or sevoflurane (group S, n=30) based anaesthesia. Postoperative analgesia was provided with morphine through a patient-controlled infusion device. Mean (SD) remifentanil infusion rate in group R was 0.23 (0.10) microg kg(-1) min(-1) and mean inspired fraction of sevoflurane in group S was 1.75 (0.70)%. Mean (SD) cumulative morphine consumption during the first 24 postoperative hours was similar between groups: 28.0 (14.2) mg (group R) vs 28.6 (12.4) mg (group S). Pain scores, were also similar between groups during this period. These data do not support the development of acute opioid tolerance after remifentanil-based anaesthesia in this type of surgery.
authors.affiliation: Hospital Clinico Universidad Católica de Chile, Departamento de Anestesiología, Santiago.
authors.forename: L I
authors.initials: LI
authors.lastname: Cortínez
authors.forename: V
authors.initials: V
authors.lastname: Brandes
authors.forename: H R
authors.initials: HR
authors.lastname: Muñoz
authors.forename: M E
authors.initials: ME
authors.lastname: Guerrero
authors.forename: M
authors.initials: M
authors.lastname: Mur
mesh_terms: D000328:Adult; D016058:Analgesia, Patient-Controlled; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000494:pharmacology*; D018685:Anesthetics, Inhalation / Q000494:pharmacology; D018686:Anesthetics, Intravenous / Q000494:pharmacology*; D004334:Drug Administration Schedule; D004347:Drug Interactions; D004361:Drug Tolerance; D005260:Female; D013509:Gynecologic Surgical Procedures; D006801:Humans; D008738:Methyl Ethers / Q000494:pharmacology; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage*; D010147:Pain Measurement; D010149:Postoperative Pain / Q000188:drug therapy; D017060:Patient Satisfaction; D010880:Piperidines / Q000494:pharmacology*; D011446:Prospective Studies; D000077208:Remifentanil; D000077149:Sevoflurane
chemical_list: D000701:Analgesics, Opioid; D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D008738:Methyl Ethers; D010880:Piperidines; D000077149:Sevoflurane; D009020:Morphine; D000077208:Remifentanil