Precision and bias of target controlled propofol infusion for sedation.

Academic Article


  • BACKGROUND: The purpose of this study is to test precision and systematic bias of a target controlled infusion (TCI) of propofol in human volunteers at two sedative concentrations. METHODS: We studied the 'Diprifusor' model (Marsh Pharmacokinetics and a Graseby 3400 infusion pump) in 18 human volunteers at two sedative target plasma concentrations (0.5 and 1.0 microg ml(-1)). Twenty minutes after infusion start or change and 20 min after discontinuation of the infusion plasma propofol concentrations were measured using liquid chromatography-mass spectroscopy (LC-MS). Plasma propofol concentrations were compared with concentrations predicted by the TCI system. Agreement of those two measures (precision and bias) was determined using regression analysis. RESULTS: We found little systematic bias but poor precision. When setting the TCI system to deliver a plasma concentration of 1.0 microg ml(-1) one can predict the actual plasma concentration with 95% confidence only within a range of 0.44-1.38 microg ml(-1). CONCLUSIONS: This finding helps to explain differences in responses to propofol sedation; pharmacokinetic variability appears to be an important factor.
  • Published In


  • Adult, Conscious Sedation, Drug Administration Schedule, Drug Delivery Systems, Drug Therapy, Computer-Assisted, Female, Gas Chromatography-Mass Spectrometry, Humans, Hypnotics and Sedatives, Infusion Pumps, Infusions, Intravenous, Linear Models, Male, Propofol
  • Digital Object Identifier (doi)

    Author List

  • Frölich MA; Dennis DM; Shuster JA; Melker RJ
  • Start Page

  • 434
  • End Page

  • 437
  • Volume

  • 94
  • Issue

  • 4