title: Dose-response and concentration-response relation of rocuronium infusion during propofol-nitrous oxide and isoflurane-nitrous oxide anaesthesia.
abstract: The dose-response and concentration-response relation of rocuronium infusion was studied in 20 adult surgical patients during propofol-nitrous oxide and isoflurane (1 MAC)-nitrous oxide anaesthesia. Neuromuscular block was kept constant, initially at 90% and then at 50% with a closed-loop feedback controller. At 90% block the steady-state infusion of rocuronium was 0.55 +/- 0.16 mg kg-1 h-1 and the corresponding concentration 1714 +/- 281 ng mL-1 in patients receiving propofol. At 50% block the corresponding infusion rate was 0.27 +/- 0.11 mg kg-1 h-1 and the concentration 1077 +/- 244 ng mL-1, respectively. At 50% block isoflurane reduced the rate of infusion by 52% (P < 0.005) and the concentration by 59% (P < 0.001); at 90% block both the mean infusion rate and the concentration of rocuronium were reduced by 35% (P < 0.005). The mean rocuronium clearance at 50% block was unaffected by the type of anaesthesia; it was 4.1 +/- 1.6 and 4.9 +/- 2.7 mL kg-1 min-1 in the groups receiving propofol and isoflurane anaesthesia, respectively. We conclude that isoflurane reduces the infusion requirements of rocuronium by changing the pharmacodynamic behaviour.
authors.affiliation: Department of Anaesthesia, University of Helsinki, Finland.
authors.forename: M
authors.initials: M
authors.lastname: Kansanaho
authors.forename: K T
authors.initials: KT
authors.lastname: Olkkola
authors.forename: J M
authors.initials: JM
authors.lastname: Wierda
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000732:Androstanols / Q000008:administration & dosage* / Q000493:pharmacokinetics; D000768:Anesthesia, General; D019162:Anesthetics, Combined; D018685:Anesthetics, Inhalation / Q000008:administration & dosage*; D018686:Anesthetics, Intravenous / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D004576:Electromyography; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D007530:Isoflurane / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D019148:Neuromuscular Blockade; D003473:Neuromuscular Nondepolarizing Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics; D009609:Nitrous Oxide / Q000008:administration & dosage*; D015742:Propofol / Q000008:administration & dosage*; D000077123:Rocuronium
chemical_list: D000732:Androstanols; D019162:Anesthetics, Combined; D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D003473:Neuromuscular Nondepolarizing Agents; D007530:Isoflurane; D009609:Nitrous Oxide; D000077123:Rocuronium; D015742:Propofol