Pharmacokinetics of Remifentanil in Anesthetized Pediatric Patients Undergoing Elective Surgery or Diagnostic Procedures

PhD§*Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina; †Departments ofAnesthesiology and Pediatrics, University of Pittsburgh School of Medicine, Children’s Hospital of Pittsburgh, Pittsburgh,Pennsylvania; ‡Department of Anesthesiology, Harvard Medical School, and Boston Children’s Hospital, Boston,Massachusetts; and §Glaxo Wellcome, Inc., Research Triangle Park, North CarolinaRemifentanil hydrochloride is an ultra-short-actingopioid that undergoes rapid metabolism by tissue andplasma esterases. We aimed to characterize the phar-macokinetics and determine the hemodynamic profileof remifentanil after a single-bolus dose in childrenaged 0 to 18 yr. Forty-two children undergoing electivesurgical procedures received remifentanil 5 g/kg in-fusedover1min.Patientsweredividedintoagegroupsasfollows:younginfants(2mo),olderinfants(2moto 2 yr), young children (2 to 7 yr), older children (7to13yr),adolescents(13to 16yr),andyoungadults(16 to 18 yr). Arterial blood samples were collectedand analyzed by mass spectroscopy to determineremifentanil pharmacokinetic profiles. Hemodynamicmeasurementsforremifentanil’seffectweremadeafterthe infusion. Methods of statistical analysis includedanalysis of variance and linear regression, with signifi-cance at