title: Pharmacokinetic model-driven infusion of fentanyl in children.
abstract: BACKGROUND
  This study determined the accuracy of previously defined adult fentanyl pharmacokinetics in children having surgery; from this population, the pharmacokinetics of fentanyl were characterized in children when administered via a computerized assisted continuous-infusion device.
  
  
  METHODS
  Twenty children between the ages of 2.7 and 11 y scheduled to undergo elective noncardiac surgery were studied. After induction, anesthesia was maintained with 60% nitrous oxide in oxygen supplemented with fentanyl (n = 10) or fentanyl plus isoflurane (n = 10). Fentanyl was administered via computerized assisted continuous-infusion to target concentrations determined by clinical requirements. Plasma fentanyl concentrations were measured and used to evaluate the performance of the fentanyl pharmacokinetics and then to determine a new set of pharmacokinetic parameters and the variance in the context-sensitive half-times simulated for these patients.
  
  
  RESULTS
  The original adult fentanyl pharmacokinetics resulted in a positive bias (10.4%), indicating that measured concentrations were mostly greater than predicted. A two-compartment model with age and weight as covariates provided the optimal pharmacokinetic parameters. These resulted in a residual performance error of -1.1% and a median absolute performance error of 17.4%. The context-sensitive times determined from this pediatric population were considerably shorter than the context-sensitive times previously published for adults.
  
  
  CONCLUSIONS
  The pharmacokinetics of fentanyl administered by computerized assisted continuous-infusion differ between adults and children. The newly derived parameters are probably more suitable to determine infusion schemes of up to 4 h in children between the ages of 2 and 11 y.
authors.affiliation: Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina 27710, USA.
authors.forename: B
authors.initials: B
authors.lastname: Ginsberg
authors.forename: S
authors.initials: S
authors.lastname: Howell
authors.forename: P S
authors.initials: PS
authors.lastname: Glass
authors.forename: J O
authors.initials: JO
authors.lastname: Margolis
authors.forename: A K
authors.initials: AK
authors.lastname: Ross
authors.forename: G L
authors.initials: GL
authors.lastname: Dear
authors.forename: S L
authors.initials: SL
authors.lastname: Shafer
mesh_terms: D018686:Anesthetics, Intravenous / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D002648:Child; D002675:Child, Preschool; D003201:Computers; D005283:Fentanyl / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D006801:Humans; D008954:Models, Biological
chemical_list: D018686:Anesthetics, Intravenous; D005283:Fentanyl