title: Pharmacokinetics of propofol in elderly coronary artery bypass graft patients under total intravenous anesthesia.
abstract: The present paper investigates the pharmacokinetics of propofol in the plasma of two elderly patients operated on under total intravenous anesthesia using propofol. A 78-year-old (patient A) and a 76-year-old (patient B), both Japanese men with unstable angina pectoris, were operated on for coronary artery bypass grafts. For the induction of anesthesia, 1.5 mg/kg propofol was administered as a single bolus infusion, and anesthesia was maintained using the step-down infusion regimens of propofol. Propofol concentration in the plasma was measured by HPLC with a fluorescence detector. The simulation curves, following the two-compartment model, fitted well to the profiles of the individual data of propofol concentrations in the plasma. When 4 mg/kg/h of propofol was administered to both patients while maintaining anesthesia, propofol concentrations in the plasma were maintained at over 1.0 microg/ml. In patient A, the propofol concentration in the plasma was 140 ng/ml at 6 h after the end of the infusion. In patient B, the propofol concentrations in the plasma were 73 ng/ml at 6 h and 35 ng/ml at 12 h after the end of the infusion. The apparent distribution volumes of patients A and B were 1.43 and 1.62 l/kg, respectively. The half-lives of propofol in the plasma of patients A and B were estimated to be 13.3 and 17.4 min as the a phase, and 10.1 and 10.5 h as the beta phase, respectively. In elderly patients with cardiac surgery, the maintenance concentrations of propofol in the plasma were enough to maintain a concentration of 1.0 microg/ml, and the half-life may be longer than previously reported values in adult patients.
authors.affiliation: Department of Clinical Pharmacy, Oita Medical University, Japan. morikawa@oita-med.ac.jp
authors.forename: Norifumi
authors.initials: N
authors.lastname: Morikawa
authors.forename: Kazushige
authors.initials: K
authors.lastname: Oishi
authors.forename: Masaharu
authors.initials: M
authors.lastname: Takeyama
authors.forename: Takayuki
authors.initials: T
authors.lastname: Noguchi
mesh_terms: D000368:Aged; D000771:Anesthesia, Intravenous; D018686:Anesthetics, Intravenous / Q000493:pharmacokinetics*; D019540:Area Under Curve; D001026:Coronary Artery Bypass; D005283:Fentanyl; D006207:Half-Life; D006801:Humans; D008297:Male; D003473:Neuromuscular Nondepolarizing Agents; D015742:Propofol / Q000493:pharmacokinetics*; D014673:Vecuronium Bromide
chemical_list: D018686:Anesthetics, Intravenous; D003473:Neuromuscular Nondepolarizing Agents; D014673:Vecuronium Bromide; D005283:Fentanyl; D015742:Propofol