title: The relationship between alfentanil distribution kinetics and cardiac output.
abstract: The relationship between cardiac output and the tissue distribution of alfentanil was investigated in seven healthy volunteers. Subjects were given 10 micrograms/kg alfentanil and 0.5 mg/kg indocyanine green. Arterial blood samples were obtained at baseline, 1 minute, every 1/2 minute until 5 minutes, and then every minute until 15 minutes after the drug injection was begun. Subsequent samples were collected to 6 hours. Cardiac output was measured continuously by use of thoracic bioimpedance. Alfentanil pharmacokinetics were modeled with both a standard three-compartment model and a four-compartmental model based in part on the two-compartmental pharmacokinetics of indocyanine green. The sum of intercompartmental clearances for both the three- and four-compartment models were significantly correlated with the measured cardiac outputs, r = 0.93 and r = 0.88, respectively. These findings indicate that the intercompartmental clearance (i.e., tissue distribution) of alfentanil is largely determined by cardiac output (i.e., tissue blood flow).
authors.affiliation: Department of Anesthesia, Northwestern University Medical School, Chicago, IL 60611.
authors.forename: T K
authors.initials: TK
authors.lastname: Henthorn
authors.forename: T C
authors.initials: TC
authors.lastname: Krejcie
authors.forename: M J
authors.initials: MJ
authors.lastname: Avram
mesh_terms: D000328:Adult; D015760:Alfentanil / Q000008:administration & dosage / Q000493:pharmacokinetics*; D002302:Cardiac Output / Q000502:physiology*; D005260:Female; D006801:Humans; D007208:Indocyanine Green / Q000008:administration & dosage / Q000493:pharmacokinetics; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D014018:Tissue Distribution
chemical_list: D015760:Alfentanil; D007208:Indocyanine Green